{"group":{"id":1,"name":"Community","lockable":false,"created_at":"2012-01-18T18:02:15.000Z","updated_at":"2026-04-06T14:01:22.000Z","description":"Problems submitted by members of the MATLAB Central community.","is_default":true,"created_by":161519,"badge_id":null,"featured":false,"trending":false,"solution_count_in_trending_period":0,"trending_last_calculated":"2026-04-06T00:00:00.000Z","image_id":null,"published":true,"community_created":false,"status_id":2,"is_default_group_for_player":false,"deleted_by":null,"deleted_at":null,"restored_by":null,"restored_at":null,"description_opc":null,"description_html":null,"published_at":null},"problems":[{"id":2959,"title":"Divide by 4","description":"Given the variable x as your input, divide it by four and put the result in y.","description_html":"\u003cp\u003eGiven the variable x as your input, divide it by four and put the result in y.\u003c/p\u003e","function_template":"function y = your_fcn_name(x)\r\n  y = (x/4);\r\nend","test_suite":"%%\r\nx = 1;\r\ny_correct = 1/4;\r\nassert(isequal(your_fcn_name(x),y_correct))\r\n","published":true,"deleted":false,"likes_count":11,"comments_count":19,"created_by":33997,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":1215,"test_suite_updated_at":null,"rescore_all_solutions":false,"group_id":1,"created_at":"2015-02-06T23:33:00.000Z","updated_at":"2026-03-17T15:40:46.000Z","published_at":"2015-02-06T23:33:03.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"relationships\":[{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/document\",\"relationshipId\":\"rId1\",\"target\":\"/matlab/document.xml\"},{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/output\",\"relationshipId\":\"rId2\",\"target\":\"/matlab/output.xml\"}],\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"relationship\":[],\"contentType\":\"application/vnd.mathworks.matlab.code.document+xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eGiven the variable x as your input, divide it by four and put the result in y.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\"},{\"partUri\":\"/matlab/output.xml\",\"contentType\":\"text/xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\" standalone=\\\"no\\\" ?\u003e\u003cembeddedOutputs\u003e\u003cmetaData\u003e\u003cevaluationState\u003emanual\u003c/evaluationState\u003e\u003clayoutState\u003ecode\u003c/layoutState\u003e\u003coutputStatus\u003eready\u003c/outputStatus\u003e\u003c/metaData\u003e\u003coutputArray type=\\\"array\\\"/\u003e\u003cregionArray type=\\\"array\\\"/\u003e\u003c/embeddedOutputs\u003e\"}]}"},{"id":2960,"title":"Divide by 4","description":"Given the variable x as your input, divide it by 4 and put the result in y.","description_html":"\u003cp\u003eGiven the variable x as your input, divide it by 4 and put the result in y.\u003c/p\u003e","function_template":"function y = onefourthx\r\n  y = x;\r\nend","test_suite":"%%\r\nx = 4;\r\ny= 1\r\ny_correct = 1;\r\nassert(isequal(onefourthx(x),y_correct))\r\n","published":true,"deleted":false,"likes_count":1,"comments_count":1,"created_by":33997,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":324,"test_suite_updated_at":"2015-02-06T23:56:14.000Z","rescore_all_solutions":true,"group_id":1,"created_at":"2015-02-06T23:39:32.000Z","updated_at":"2026-03-05T09:32:05.000Z","published_at":"2015-02-06T23:39:31.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"relationships\":[{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/document\",\"relationshipId\":\"rId1\",\"target\":\"/matlab/document.xml\"},{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/output\",\"relationshipId\":\"rId2\",\"target\":\"/matlab/output.xml\"}],\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"relationship\":[],\"contentType\":\"application/vnd.mathworks.matlab.code.document+xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eGiven the variable x as your input, divide it by 4 and put the result in y.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\"},{\"partUri\":\"/matlab/output.xml\",\"contentType\":\"text/xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\" standalone=\\\"no\\\" ?\u003e\u003cembeddedOutputs\u003e\u003cmetaData\u003e\u003cevaluationState\u003emanual\u003c/evaluationState\u003e\u003clayoutState\u003ecode\u003c/layoutState\u003e\u003coutputStatus\u003eready\u003c/outputStatus\u003e\u003c/metaData\u003e\u003coutputArray type=\\\"array\\\"/\u003e\u003cregionArray type=\\\"array\\\"/\u003e\u003c/embeddedOutputs\u003e\"}]}"},{"id":1435,"title":"Basics: Divide integers to get integer outputs in all cases","description":"Divide integers a and b in such a way that output y is always an integer (in ceil manner)","description_html":"\u003cp\u003eDivide integers a and b in such a way that output y is always an integer (in ceil manner)\u003c/p\u003e","function_template":"function y = divide_differently(a,b)\r\n  y = a;\r\nend","test_suite":"%%\r\na = [-2 2];b=3;\r\ny = [0 1];\r\nassert(isequal(divide_differently(a,b),y))\r\n%%\r\na = [-5 0];b=3;\r\ny = [-1 0];\r\nassert(isequal(divide_differently(a,b),y))","published":true,"deleted":false,"likes_count":2,"comments_count":0,"created_by":10792,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":137,"test_suite_updated_at":null,"rescore_all_solutions":false,"group_id":1,"created_at":"2013-04-19T18:54:31.000Z","updated_at":"2026-04-01T10:56:19.000Z","published_at":"2013-04-19T18:54:31.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"relationships\":[{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/document\",\"relationshipId\":\"rId1\",\"target\":\"/matlab/document.xml\"},{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/output\",\"relationshipId\":\"rId2\",\"target\":\"/matlab/output.xml\"}],\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"relationship\":[],\"contentType\":\"application/vnd.mathworks.matlab.code.document+xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eDivide integers a and b in such a way that output y is always an integer (in ceil manner)\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\"},{\"partUri\":\"/matlab/output.xml\",\"contentType\":\"text/xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\" standalone=\\\"no\\\" ?\u003e\u003cembeddedOutputs\u003e\u003cmetaData\u003e\u003cevaluationState\u003emanual\u003c/evaluationState\u003e\u003clayoutState\u003ecode\u003c/layoutState\u003e\u003coutputStatus\u003eready\u003c/outputStatus\u003e\u003c/metaData\u003e\u003coutputArray type=\\\"array\\\"/\u003e\u003cregionArray type=\\\"array\\\"/\u003e\u003c/embeddedOutputs\u003e\"}]}"},{"id":1833,"title":"Usage of java.math : Add, Multiply, Pow","description":"This challenge is an introduction to the wonderful word of java.math that allows unlimited precision calculations.  The primary reference sites are \u003chttp://docs.oracle.com/javase/1.5.0/docs/api/java/lang/Number.html Java Math\u003e, \u003chttp://docs.oracle.com/javase/1.5.0/docs/api/java/math/BigDecimal.html Java BigDecimal\u003e, and \u003chttp://docs.oracle.com/javase/1.5.0/docs/api/java/math/BigInteger.html Java BigInteger\u003e.\r\n\r\nThe usage of BigDecimal functions add, multiply, and pow will be tested.\r\n\r\nJava Math tutorial: (Simplified summary that is believed correct)\r\n\r\n  vd-decimal value, vstr-string, vi-integer value \r\n  xBD=java.math.BigDecimal(vd);  % valid vd,vstr,vi creates xBD a BigDecimal variable\r\n  import java.math.*;  % simplifies statements\r\n  xBD=BigDecimal(vstr);\r\n  x2pwrBD=xBD.pow(vi); % Invalid: vd,vstr,BD\r\n  xplusyBD=xBD.add(BigDecimal(y)); % add input requires BD type\r\n  xmultiplyzBD=xBD.multiply(BigDecimal(z));  % multiply input requires BD type\r\n  \r\n  To convert java to string of unlimited length can be achieved via java toString or Matlab char\r\n  \r\n  xstr=toString(xBD)  or xstr=char(xBD) \r\n\r\n*Input:* X,Y, function_case  [X,Y double or str, function 1:X+Y, 2:X*Y, 3: X^Y(double)\r\n\r\n*Output:* z  (char variable)\r\n\r\n*Future Challenges:*\r\n\r\n  1. nchoosek_large (full precision)\r\n  2. Next Prime\r\n  3. factor_large\r\n\r\n4. \u003chttp://www.mathworks.com/matlabcentral/cody/problems/1854-factorial-unlimited-size-java-math Factorial\u003e","description_html":"\u003cp\u003eThis challenge is an introduction to the wonderful word of java.math that allows unlimited precision calculations.  The primary reference sites are \u003ca href = \"http://docs.oracle.com/javase/1.5.0/docs/api/java/lang/Number.html\"\u003eJava Math\u003c/a\u003e, \u003ca href = \"http://docs.oracle.com/javase/1.5.0/docs/api/java/math/BigDecimal.html\"\u003eJava BigDecimal\u003c/a\u003e, and \u003ca href = \"http://docs.oracle.com/javase/1.5.0/docs/api/java/math/BigInteger.html\"\u003eJava BigInteger\u003c/a\u003e.\u003c/p\u003e\u003cp\u003eThe usage of BigDecimal functions add, multiply, and pow will be tested.\u003c/p\u003e\u003cp\u003eJava Math tutorial: (Simplified summary that is believed correct)\u003c/p\u003e\u003cpre class=\"language-matlab\"\u003evd-decimal value, vstr-string, vi-integer value \r\nxBD=java.math.BigDecimal(vd);  % valid vd,vstr,vi creates xBD a BigDecimal variable\r\nimport java.math.*;  % simplifies statements\r\nxBD=BigDecimal(vstr);\r\nx2pwrBD=xBD.pow(vi); % Invalid: vd,vstr,BD\r\nxplusyBD=xBD.add(BigDecimal(y)); % add input requires BD type\r\nxmultiplyzBD=xBD.multiply(BigDecimal(z));  % multiply input requires BD type\r\n\u003c/pre\u003e\u003cpre class=\"language-matlab\"\u003eTo convert java to string of unlimited length can be achieved via java toString or Matlab char\r\n\u003c/pre\u003e\u003cpre class=\"language-matlab\"\u003exstr=toString(xBD)  or xstr=char(xBD) \r\n\u003c/pre\u003e\u003cp\u003e\u003cb\u003eInput:\u003c/b\u003e X,Y, function_case  [X,Y double or str, function 1:X+Y, 2:X*Y, 3: X^Y(double)\u003c/p\u003e\u003cp\u003e\u003cb\u003eOutput:\u003c/b\u003e z  (char variable)\u003c/p\u003e\u003cp\u003e\u003cb\u003eFuture Challenges:\u003c/b\u003e\u003c/p\u003e\u003cpre class=\"language-matlab\"\u003e1. nchoosek_large (full precision)\r\n2. Next Prime\r\n3. factor_large\r\n\u003c/pre\u003e\u003cp\u003e4. \u003ca href = \"http://www.mathworks.com/matlabcentral/cody/problems/1854-factorial-unlimited-size-java-math\"\u003eFactorial\u003c/a\u003e\u003c/p\u003e","function_template":"function zstr=java_math(x,y,select)\r\n import java.math.*\r\n\r\n switch select\r\n    case 1 % add x+y\r\n     zBD=x+y;\r\n    case 2 % multiply  x*y\r\n     zBD=x*y;\r\n    case 3 % power  x^y\r\n     zBD=x^y;\r\n     \r\n end\r\n zstr=char(zBD);\r\n\r\nend","test_suite":"%%\r\nx=2;\r\ny=64;\r\n% power\r\nzstr=java_math(x,y,3);\r\nassert(strcmp(zstr,'18446744073709551616'),sprintf('zstr=%s\\n',zstr))\r\n%%\r\nxstr='18446744073709551615';\r\ny=3;\r\n%Add\r\nzstr=java_math(xstr,y,1);\r\nassert(strcmp(zstr,'18446744073709551618'),sprintf('zstr=%s\\n',zstr))\r\n%%\r\nx=2^53;  % largest eps==1 double\r\ny=2^11;\r\n%Multiply\r\nzstr=java_math(x,y,2);\r\nassert(strcmp(zstr,'18446744073709551616'),sprintf('zstr=%s\\n',zstr))\r\n%%\r\nx=2^53;  % largest valid double\r\ny=2^12;\r\n% Multiply\r\nzstr=java_math(x,y,2);\r\nassert(strcmp(zstr,'36893488147419103232'),sprintf('zstr=%s\\n',zstr))\r\n%%\r\nx=randi(10);\r\ny=randi(100);\r\nzstr=java_math(x,y,1);\r\nassert(strcmp(zstr,num2str(x+y)),sprintf('x=%2i y=%3i x+y=%5i zstr=%s\\n',x,y,x+y,zstr))\r\n%%\r\nx=randi(10);\r\ny=randi(100);\r\nzstr=java_math(x,y,2);\r\nassert(strcmp(zstr,num2str(x*y)),sprintf('x=%2i y=%3i x*y=%5i zstr=%s\\n',x,y,x*y,zstr))\r\n%%\r\nx=randi(20);\r\ny=randi(5);\r\nzstr=java_math(x,y,3);\r\nassert(strcmp(zstr,num2str(x^y)),sprintf('x=%2i y=%3i x^y=%8i zstr=%s\\n',x,y,x^y,zstr))\r\n\r\n\r\n","published":true,"deleted":false,"likes_count":4,"comments_count":3,"created_by":3097,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":37,"test_suite_updated_at":null,"rescore_all_solutions":false,"group_id":1,"created_at":"2013-08-18T17:42:26.000Z","updated_at":"2025-12-10T01:06:03.000Z","published_at":"2013-08-18T19:02:27.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"relationships\":[{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/document\",\"targetMode\":\"\",\"relationshipId\":\"rId1\",\"target\":\"/matlab/document.xml\"},{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/output\",\"targetMode\":\"\",\"relationshipId\":\"rId2\",\"target\":\"/matlab/output.xml\"}],\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"relationship\":[],\"contentType\":\"application/vnd.mathworks.matlab.code.document+xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\\n\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eThis challenge is an introduction to the wonderful word of java.math that allows unlimited precision calculations. The primary reference sites are\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:hyperlink w:docLocation=\\\"http://docs.oracle.com/javase/1.5.0/docs/api/java/lang/Number.html\\\"\u003e\u003cw:r\u003e\u003cw:t\u003eJava Math\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:hyperlink\u003e\u003cw:r\u003e\u003cw:t\u003e,\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:hyperlink w:docLocation=\\\"http://docs.oracle.com/javase/1.5.0/docs/api/java/math/BigDecimal.html\\\"\u003e\u003cw:r\u003e\u003cw:t\u003eJava BigDecimal\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:hyperlink\u003e\u003cw:r\u003e\u003cw:t\u003e, and\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:hyperlink w:docLocation=\\\"http://docs.oracle.com/javase/1.5.0/docs/api/java/math/BigInteger.html\\\"\u003e\u003cw:r\u003e\u003cw:t\u003eJava BigInteger\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:hyperlink\u003e\u003cw:r\u003e\u003cw:t\u003e.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eThe usage of BigDecimal functions add, multiply, and pow will be tested.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eJava Math tutorial: (Simplified summary that is believed correct)\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"code\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003e\u003c![CDATA[vd-decimal value, vstr-string, vi-integer value \\nxBD=java.math.BigDecimal(vd);  % valid vd,vstr,vi creates xBD a BigDecimal variable\\nimport java.math.*;  % simplifies statements\\nxBD=BigDecimal(vstr);\\nx2pwrBD=xBD.pow(vi); % Invalid: vd,vstr,BD\\nxplusyBD=xBD.add(BigDecimal(y)); % add input requires BD type\\nxmultiplyzBD=xBD.multiply(BigDecimal(z));  % multiply input requires BD type\\n\\nTo convert java to string of unlimited length can be achieved via java toString or Matlab char\\n\\nxstr=toString(xBD)  or xstr=char(xBD)]]\u003e\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:b/\u003e\u003c/w:rPr\u003e\u003cw:t\u003eInput:\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e X,Y, function_case [X,Y double or str, function 1:X+Y, 2:X*Y, 3: X^Y(double)\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:b/\u003e\u003c/w:rPr\u003e\u003cw:t\u003eOutput:\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e z (char variable)\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:b/\u003e\u003c/w:rPr\u003e\u003cw:t\u003eFuture Challenges:\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"code\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003e\u003c![CDATA[1. nchoosek_large (full precision)\\n2. Next Prime\\n3. factor_large]]\u003e\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003e4.\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:hyperlink w:docLocation=\\\"http://www.mathworks.com/matlabcentral/cody/problems/1854-factorial-unlimited-size-java-math\\\"\u003e\u003cw:r\u003e\u003cw:t\u003eFactorial\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:hyperlink\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\"},{\"partUri\":\"/matlab/output.xml\",\"contentType\":\"text/xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\" standalone=\\\"no\\\" ?\u003e\u003cembeddedOutputs\u003e\u003cmetaData\u003e\u003cevaluationState\u003emanual\u003c/evaluationState\u003e\u003clayoutState\u003ecode\u003c/layoutState\u003e\u003coutputStatus\u003eready\u003c/outputStatus\u003e\u003c/metaData\u003e\u003coutputArray type=\\\"array\\\"/\u003e\u003cregionArray type=\\\"array\\\"/\u003e\u003c/embeddedOutputs\u003e\"}]}"},{"id":2230,"title":"Back to basics - array operations","description":"Without performing actual arithmetic operations on arrays, return feasibility of operation as true or false. True if given operation can be performed on given matrices, else false.\r\nExample\r\n Operation = 'Add'\r\n Matrices are:\r\n  a = magic(3);\r\n  b = [2 2; 2 2; 2 2]\r\nResult: false, since size of a and b should be same to perform \"Add\" operation.","description_html":"\u003cdiv style = \"text-align: start; line-height: 20.4333px; min-height: 0px; white-space: normal; color: rgb(0, 0, 0); font-family: Menlo, Monaco, Consolas, monospace; font-style: normal; font-size: 14px; font-weight: 400; text-decoration: rgb(0, 0, 0); white-space: normal; \"\u003e\u003cdiv style=\"block-size: 194.733px; display: block; min-width: 0px; padding-block-start: 0px; padding-top: 0px; perspective-origin: 407px 97.3667px; transform-origin: 407px 97.3667px; vertical-align: baseline; \"\u003e\u003cdiv style=\"block-size: 42px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 21px; text-align: left; transform-origin: 384px 21px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 369.5px 8px; transform-origin: 369.5px 8px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003eWithout performing actual arithmetic operations on arrays, return feasibility of operation as true or false. True if given operation can be performed on given matrices, else false.\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 21px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 10.5px; text-align: left; transform-origin: 384px 10.5px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 26.5px 8px; transform-origin: 26.5px 8px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003eExample\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"background-color: rgb(247, 247, 247); block-size: 81.7333px; border-bottom-left-radius: 4px; border-bottom-right-radius: 4px; border-end-end-radius: 4px; border-end-start-radius: 4px; border-start-end-radius: 4px; border-start-start-radius: 4px; border-top-left-radius: 4px; border-top-right-radius: 4px; margin-block-end: 10px; margin-block-start: 10px; margin-bottom: 10px; margin-inline-end: 3px; margin-inline-start: 3px; margin-left: 3px; margin-right: 3px; margin-top: 10px; perspective-origin: 404px 40.8667px; transform-origin: 404px 40.8667px; margin-left: 3px; margin-top: 10px; margin-bottom: 10px; margin-right: 3px; \"\u003e\u003cdiv style=\"background-color: rgba(0, 0, 0, 0); block-size: 20.4333px; border-bottom-left-radius: 0px; border-bottom-right-radius: 0px; border-end-end-radius: 0px; border-end-start-radius: 0px; border-inline-end-color: rgb(233, 233, 233); border-inline-end-style: solid; border-inline-end-width: 1px; border-inline-start-color: rgb(233, 233, 233); border-inline-start-style: solid; border-inline-start-width: 1px; border-left-color: rgb(233, 233, 233); border-left-style: solid; border-left-width: 1px; border-right-color: rgb(233, 233, 233); border-right-style: solid; border-right-width: 1px; border-start-end-radius: 0px; border-start-start-radius: 0px; border-top-left-radius: 0px; border-top-right-radius: 0px; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; min-block-size: 18px; min-height: 18px; padding-inline-start: 4px; padding-left: 4px; perspective-origin: 404px 10.2167px; transform-origin: 404px 10.2167px; white-space: nowrap; \"\u003e\u003cspan style=\"block-size: auto; border-inline-end-color: rgb(0, 0, 0); border-inline-end-style: none; border-inline-end-width: 0px; border-inline-start-color: rgb(0, 0, 0); border-inline-start-style: none; border-inline-start-width: 0px; border-left-color: rgb(0, 0, 0); border-left-style: none; border-left-width: 0px; border-right-color: rgb(0, 0, 0); border-right-style: none; border-right-width: 0px; display: inline; margin-inline-end: 45px; margin-right: 45px; min-block-size: 0px; min-height: 0px; padding-inline-start: 0px; padding-left: 0px; perspective-origin: 72px 8.5px; tab-size: 4; transform-origin: 72px 8.5px; unicode-bidi: normal; white-space: pre; margin-right: 45px; \"\u003e\u003cspan style=\"margin-inline-end: 0px; margin-right: 0px; perspective-origin: 52px 8.5px; transform-origin: 52px 8.5px; \"\u003e Operation = \u003c/span\u003e\u003cspan style=\"border-block-end-color: rgb(170, 4, 249); border-block-start-color: rgb(170, 4, 249); border-bottom-color: rgb(170, 4, 249); border-inline-end-color: rgb(170, 4, 249); border-inline-start-color: rgb(170, 4, 249); border-left-color: rgb(170, 4, 249); border-right-color: rgb(170, 4, 249); border-top-color: rgb(170, 4, 249); caret-color: rgb(170, 4, 249); color: rgb(170, 4, 249); column-rule-color: rgb(170, 4, 249); margin-inline-end: 0px; margin-right: 0px; outline-color: rgb(170, 4, 249); perspective-origin: 20px 8.5px; text-decoration-color: rgb(170, 4, 249); text-emphasis-color: rgb(170, 4, 249); transform-origin: 20px 8.5px; \"\u003e'Add'\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"background-color: rgba(0, 0, 0, 0); block-size: 20.4333px; border-bottom-left-radius: 0px; border-bottom-right-radius: 0px; border-end-end-radius: 0px; border-end-start-radius: 0px; border-inline-end-color: rgb(233, 233, 233); border-inline-end-style: solid; border-inline-end-width: 1px; border-inline-start-color: rgb(233, 233, 233); border-inline-start-style: solid; border-inline-start-width: 1px; border-left-color: rgb(233, 233, 233); border-left-style: solid; border-left-width: 1px; border-right-color: rgb(233, 233, 233); border-right-style: solid; border-right-width: 1px; border-start-end-radius: 0px; border-start-start-radius: 0px; border-top-left-radius: 0px; border-top-right-radius: 0px; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; min-block-size: 18px; min-height: 18px; padding-inline-start: 4px; padding-left: 4px; perspective-origin: 404px 10.2167px; transform-origin: 404px 10.2167px; white-space: nowrap; \"\u003e\u003cspan style=\"block-size: auto; border-inline-end-color: rgb(0, 0, 0); border-inline-end-style: none; border-inline-end-width: 0px; border-inline-start-color: rgb(0, 0, 0); border-inline-start-style: none; border-inline-start-width: 0px; border-left-color: rgb(0, 0, 0); border-left-style: none; border-left-width: 0px; border-right-color: rgb(0, 0, 0); border-right-style: none; border-right-width: 0px; display: inline; margin-inline-end: 45px; margin-right: 45px; min-block-size: 0px; min-height: 0px; padding-inline-start: 0px; padding-left: 0px; perspective-origin: 56px 8.5px; tab-size: 4; transform-origin: 56px 8.5px; unicode-bidi: normal; white-space: pre; margin-right: 45px; \"\u003e\u003cspan style=\"margin-inline-end: 0px; margin-right: 0px; perspective-origin: 40px 8.5px; transform-origin: 40px 8.5px; \"\u003e Matrices \u003c/span\u003e\u003cspan style=\"border-block-end-color: rgb(170, 4, 249); border-block-start-color: rgb(170, 4, 249); border-bottom-color: rgb(170, 4, 249); border-inline-end-color: rgb(170, 4, 249); border-inline-start-color: rgb(170, 4, 249); border-left-color: rgb(170, 4, 249); border-right-color: rgb(170, 4, 249); border-top-color: rgb(170, 4, 249); caret-color: rgb(170, 4, 249); color: rgb(170, 4, 249); column-rule-color: rgb(170, 4, 249); margin-inline-end: 0px; margin-right: 0px; outline-color: rgb(170, 4, 249); perspective-origin: 16px 8.5px; text-decoration-color: rgb(170, 4, 249); text-emphasis-color: rgb(170, 4, 249); transform-origin: 16px 8.5px; \"\u003eare:\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"background-color: rgba(0, 0, 0, 0); block-size: 20.4333px; border-bottom-left-radius: 0px; border-bottom-right-radius: 0px; border-end-end-radius: 0px; border-end-start-radius: 0px; border-inline-end-color: rgb(233, 233, 233); border-inline-end-style: solid; border-inline-end-width: 1px; border-inline-start-color: rgb(233, 233, 233); border-inline-start-style: solid; border-inline-start-width: 1px; border-left-color: rgb(233, 233, 233); border-left-style: solid; border-left-width: 1px; border-right-color: rgb(233, 233, 233); border-right-style: solid; border-right-width: 1px; border-start-end-radius: 0px; border-start-start-radius: 0px; border-top-left-radius: 0px; border-top-right-radius: 0px; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; min-block-size: 18px; min-height: 18px; padding-inline-start: 4px; padding-left: 4px; perspective-origin: 404px 10.2167px; transform-origin: 404px 10.2167px; white-space: nowrap; \"\u003e\u003cspan style=\"block-size: auto; border-inline-end-color: rgb(0, 0, 0); border-inline-end-style: none; border-inline-end-width: 0px; border-inline-start-color: rgb(0, 0, 0); border-inline-start-style: none; border-inline-start-width: 0px; border-left-color: rgb(0, 0, 0); border-left-style: none; border-left-width: 0px; border-right-color: rgb(0, 0, 0); border-right-style: none; border-right-width: 0px; display: inline; margin-inline-end: 45px; margin-right: 45px; min-block-size: 0px; min-height: 0px; padding-inline-start: 0px; padding-left: 0px; perspective-origin: 60px 8.5px; tab-size: 4; transform-origin: 60px 8.5px; unicode-bidi: normal; white-space: pre; margin-right: 45px; \"\u003e\u003cspan style=\"margin-inline-end: 0px; margin-right: 0px; \"\u003e  a = magic(3);\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"background-color: rgba(0, 0, 0, 0); block-size: 20.4333px; border-bottom-left-radius: 0px; border-bottom-right-radius: 0px; border-end-end-radius: 0px; border-end-start-radius: 0px; border-inline-end-color: rgb(233, 233, 233); border-inline-end-style: solid; border-inline-end-width: 1px; border-inline-start-color: rgb(233, 233, 233); border-inline-start-style: solid; border-inline-start-width: 1px; border-left-color: rgb(233, 233, 233); border-left-style: solid; border-left-width: 1px; border-right-color: rgb(233, 233, 233); border-right-style: solid; border-right-width: 1px; border-start-end-radius: 0px; border-start-start-radius: 0px; border-top-left-radius: 0px; border-top-right-radius: 0px; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; min-block-size: 18px; min-height: 18px; padding-inline-start: 4px; padding-left: 4px; perspective-origin: 404px 10.2167px; transform-origin: 404px 10.2167px; white-space: nowrap; \"\u003e\u003cspan style=\"block-size: auto; border-inline-end-color: rgb(0, 0, 0); border-inline-end-style: none; border-inline-end-width: 0px; border-inline-start-color: rgb(0, 0, 0); border-inline-start-style: none; border-inline-start-width: 0px; border-left-color: rgb(0, 0, 0); border-left-style: none; border-left-width: 0px; border-right-color: rgb(0, 0, 0); border-right-style: none; border-right-width: 0px; display: inline; margin-inline-end: 45px; margin-right: 45px; min-block-size: 0px; min-height: 0px; padding-inline-start: 0px; padding-left: 0px; perspective-origin: 84px 8.5px; tab-size: 4; transform-origin: 84px 8.5px; unicode-bidi: normal; white-space: pre; margin-right: 45px; \"\u003e\u003cspan style=\"margin-inline-end: 0px; margin-right: 0px; \"\u003e  b = [2 2; 2 2; 2 2]\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 21px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 10px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 10px; perspective-origin: 384px 10.5px; text-align: left; transform-origin: 384px 10.5px; white-space: pre-wrap; margin-left: 4px; margin-top: 10px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 247.5px 8px; transform-origin: 247.5px 8px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003eResult: false, since size of a and b should be same to perform \"Add\" operation.\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003c/div\u003e\u003c/div\u003e","function_template":"function y = ArrayOperation(a,b,operation)\r\n  y = true;\r\nend","test_suite":"%%\r\nx = magic(3);\r\ny = eye(3);\r\noperation = 'Add';\r\ny_correct = true;\r\nassert(isequal(ArrayOperation(x,y,operation),y_correct))\r\n\r\n%%\r\nx = magic(3);\r\ny = eye(2);\r\noperation = 'Add';\r\ny_correct = false;\r\nassert(isequal(ArrayOperation(x,y,operation),y_correct))\r\n\r\n%%\r\nx = magic(3);\r\ny = repmat(3,3,3);\r\noperation = 'Multiply';\r\ny_correct = true;\r\nassert(isequal(ArrayOperation(x,y,operation),y_correct))\r\n\r\n%%\r\nx = magic(3);\r\ny = repmat(3,3,2);\r\noperation = 'Multiply';\r\ny_correct = true;\r\nassert(isequal(ArrayOperation(x,y,operation),y_correct))\r\n\r\n%%\r\nx = 3;\r\ny = repmat(3,3,2);\r\noperation = 'Add';\r\ny_correct = true;\r\nassert(isequal(ArrayOperation(x,y,operation),y_correct))\r\n\r\n%%\r\nx = 3;\r\ny = repmat(3,3,2);\r\noperation = 'Subtract';\r\ny_correct = true;\r\nassert(isequal(ArrayOperation(x,y,operation),y_correct))\r\n\r\n%%\r\nx = 3;\r\ny = repmat(3,3,2);\r\noperation = 'Divide';\r\ny_correct = false;\r\nassert(isequal(ArrayOperation(x,y,operation),y_correct))\r\n\r\n%%\r\nx = 3;\r\ny = repmat(3,3,2);\r\noperation = 'Divide';\r\ny_correct = true;\r\nassert(isequal(ArrayOperation(y,x,operation),y_correct))\r\n\r\n%%\r\nx = ones(3,2);\r\ny = repmat(3,3,2);\r\noperation = 'Divide';\r\ny_correct = true;\r\nassert(isequal(ArrayOperation(x,y,operation),y_correct))\r\n\r\n%%\r\nx = 3;\r\ny = ones(5,7);\r\noperation = 'Multiply';\r\ny_correct = true;\r\nassert(isequal(ArrayOperation(x,y,operation),y_correct))\r\n\r\n%%\r\nx = ones(3,3);\r\ny = repmat(3,3,2);\r\noperation = 'Divide';\r\ny_correct = false;\r\nassert(isequal(ArrayOperation(x,y,operation),y_correct))","published":true,"deleted":false,"likes_count":1,"comments_count":2,"created_by":16381,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":53,"test_suite_updated_at":"2022-02-22T05:49:00.000Z","rescore_all_solutions":false,"group_id":1,"created_at":"2014-03-03T22:31:03.000Z","updated_at":"2025-12-04T17:14:15.000Z","published_at":"2014-03-03T22:33:40.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"contentType\":\"application/vnd.mathworks.matlab.code.document+xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eWithout performing actual arithmetic operations on arrays, return feasibility of operation as true or false. True if given operation can be performed on given matrices, else false.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eExample\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"code\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003e\u003c![CDATA[ Operation = 'Add'\\n Matrices are:\\n  a = magic(3);\\n  b = [2 2; 2 2; 2 2]]]\u003e\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eResult: false, since size of a and b should be same to perform \\\"Add\\\" operation.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\",\"relationship\":null}],\"relationships\":[{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/document\",\"target\":\"/matlab/document.xml\",\"relationshipId\":\"rId1\"}]}"},{"id":2432,"title":"Equation Times (of the day)","description":"Many times throughout the day can represent mathematical equations. In this problem, we focus on times that include the four basic operations (+,-,*,/). For example, 6:17 can be written as 6=1+7. Write a function that determines if the given time (restricted to three digits in 12-hour time, 1:00 to 9:59) is an equation time, and if so, which basic operation it uses. There are also four types of equations that are categorized here, and a given time can fit more than one category:\r\n\r\n - equation written forward, \"=\" doesn't coincide with \":\" --\u003e add 1 to output (e.g., 2:35, 2+3=5)\r\n\r\n - equation written forward, \"=\" does coincide with \":\" -- \u003e add 100 to output (e.g., 2:53, 2=5-3)\r\n\r\n - equation written backward, \"=\" doesn't coincide with \":\" --\u003e add 10 to output (e.g., 3:26, 6=2*3)\r\n\r\n - equation written backward, \"=\" does coincide with \":\" --\u003e add 1000 to output (e.g., 4:28, 8/2=4)\r\n\r\nNote that some of these combinations are tied to each other due to the commutative nature of + and * and the inverse relation of +,- and **,/. The output should be a 4x2 matrix with 0s or 1s in the first column dependent on whether each operation (+,-,*,/) is applicable to a given time and the totals in the second column. Examples include: \r\n\r\n4:22 | out = [1 1100; 1 1; 1 1100; 1 1]; since 4=2+2, 2+2=4; 4-2=2; 4=2*2, 2*2=4; 4/2=2.\r\n\r\n5:15 | out = [0 0; 0 0; 1 1111; 1 1001]; since 5*1=5, 5=1*5, 5*1=5, 5=1*5; 5/1=5, 5/1=5.\r\n\r\nThis problem is related to \u003chttp://www.mathworks.com/matlabcentral/cody/problems/2431-power-times-of-the-day Problem 2431\u003e and \u003chttp://www.mathworks.com/matlabcentral/cody/problems/2433-consecutive-equation-times-of-the-day Problem 2433\u003e.","description_html":"\u003cp\u003eMany times throughout the day can represent mathematical equations. In this problem, we focus on times that include the four basic operations (+,-,*,/). For example, 6:17 can be written as 6=1+7. Write a function that determines if the given time (restricted to three digits in 12-hour time, 1:00 to 9:59) is an equation time, and if so, which basic operation it uses. There are also four types of equations that are categorized here, and a given time can fit more than one category:\u003c/p\u003e\u003cpre\u003e - equation written forward, \"=\" doesn't coincide with \":\" --\u0026gt; add 1 to output (e.g., 2:35, 2+3=5)\u003c/pre\u003e\u003cpre\u003e - equation written forward, \"=\" does coincide with \":\" -- \u0026gt; add 100 to output (e.g., 2:53, 2=5-3)\u003c/pre\u003e\u003cpre\u003e - equation written backward, \"=\" doesn't coincide with \":\" --\u0026gt; add 10 to output (e.g., 3:26, 6=2*3)\u003c/pre\u003e\u003cpre\u003e - equation written backward, \"=\" does coincide with \":\" --\u0026gt; add 1000 to output (e.g., 4:28, 8/2=4)\u003c/pre\u003e\u003cp\u003eNote that some of these combinations are tied to each other due to the commutative nature of + and * and the inverse relation of +,- and ,/. The output should be a 4x2 matrix with 0s or 1s in the first column dependent on whether each operation (+,-,*,/) is applicable to a given time and the totals in the second column. Examples include:\u003c/p\u003e\u003cp\u003e4:22 | out = [1 1100; 1 1; 1 1100; 1 1]; since 4=2+2, 2+2=4; 4-2=2; 4=2*2, 2*2=4; 4/2=2.\u003c/p\u003e\u003cp\u003e5:15 | out = [0 0; 0 0; 1 1111; 1 1001]; since 5*1=5, 5=1*5, 5*1=5, 5=1*5; 5/1=5, 5/1=5.\u003c/p\u003e\u003cp\u003eThis problem is related to \u003ca href = \"http://www.mathworks.com/matlabcentral/cody/problems/2431-power-times-of-the-day\"\u003eProblem 2431\u003c/a\u003e and \u003ca href = \"http://www.mathworks.com/matlabcentral/cody/problems/2433-consecutive-equation-times-of-the-day\"\u003eProblem 2433\u003c/a\u003e.\u003c/p\u003e","function_template":"function out = equation_time(time)\r\n out = 0;\r\nend","test_suite":"%%\r\ntime = '4:22';\r\ny_correct = [1 1100;\r\n\t1 1;\r\n\t1 1100;\r\n\t1 1];\r\nassert(isequal(equation_time(time),y_correct))\r\n\r\n%%\r\ntime = '2:38';\r\ny_correct = zeros(4,2);\r\nassert(isequal(equation_time(time),y_correct))\r\n\r\n%%\r\ntime = '5:15';\r\ny_correct = [0 0;\r\n\t0 0;\r\n\t1 1111;\r\n \t1 1001];\r\nassert(isequal(equation_time(time),y_correct))\r\n\r\n%%\r\ntime = '1:23';\r\ny_correct = [1 11;\r\n\t1 1000;\r\n\t0 0;\r\n \t0 0];\r\nassert(isequal(equation_time(time),y_correct))\r\n\r\n%%\r\ntime = '1:02';\r\ny_correct = zeros(4,2);\r\nassert(isequal(equation_time(time),y_correct))\r\n\r\n%%\r\ntime = '1:11';\r\ny_correct = [0 0;\r\n\t0 0;\r\n\t1 1111;\r\n \t1 1111];\r\nassert(isequal(equation_time(time),y_correct))\r\n\r\n%%\r\ntime = '2:11';\r\ny_correct = [1 1100;\r\n\t1 1;\r\n\t0 0;\r\n \t0 0];\r\nassert(isequal(equation_time(time),y_correct))","published":true,"deleted":false,"likes_count":3,"comments_count":0,"created_by":26769,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":79,"test_suite_updated_at":null,"rescore_all_solutions":false,"group_id":45,"created_at":"2014-07-15T18:39:02.000Z","updated_at":"2026-01-15T14:29:10.000Z","published_at":"2014-07-15T18:39:02.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"relationships\":[{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/document\",\"targetMode\":\"\",\"relationshipId\":\"rId1\",\"target\":\"/matlab/document.xml\"},{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/output\",\"targetMode\":\"\",\"relationshipId\":\"rId2\",\"target\":\"/matlab/output.xml\"}],\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"relationship\":[],\"contentType\":\"application/vnd.mathworks.matlab.code.document+xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\\n\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eMany times throughout the day can represent mathematical equations. In this problem, we focus on times that include the four basic operations (+,-,*,/). For example, 6:17 can be written as 6=1+7. Write a function that determines if the given time (restricted to three digits in 12-hour time, 1:00 to 9:59) is an equation time, and if so, which basic operation it uses. There are also four types of equations that are categorized here, and a given time can fit more than one category:\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"code\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003e\u003c![CDATA[ - equation written forward, \\\"=\\\" doesn't coincide with \\\":\\\" --\u003e add 1 to output (e.g., 2:35, 2+3=5)\\n\\n - equation written forward, \\\"=\\\" does coincide with \\\":\\\" -- \u003e add 100 to output (e.g., 2:53, 2=5-3)\\n\\n - equation written backward, \\\"=\\\" doesn't coincide with \\\":\\\" --\u003e add 10 to output (e.g., 3:26, 6=2*3)\\n\\n - equation written backward, \\\"=\\\" does coincide with \\\":\\\" --\u003e add 1000 to output (e.g., 4:28, 8/2=4)]]\u003e\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eNote that some of these combinations are tied to each other due to the commutative nature of + and * and the inverse relation of +,- and ,/. The output should be a 4x2 matrix with 0s or 1s in the first column dependent on whether each operation (+,-,*,/) is applicable to a given time and the totals in the second column. Examples include:\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003e4:22 | out = [1 1100; 1 1; 1 1100; 1 1]; since 4=2+2, 2+2=4; 4-2=2; 4=2*2, 2*2=4; 4/2=2.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003e5:15 | out = [0 0; 0 0; 1 1111; 1 1001]; since 5*1=5, 5=1*5, 5*1=5, 5=1*5; 5/1=5, 5/1=5.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eThis problem is related to\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:hyperlink w:docLocation=\\\"http://www.mathworks.com/matlabcentral/cody/problems/2431-power-times-of-the-day\\\"\u003e\u003cw:r\u003e\u003cw:t\u003eProblem 2431\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:hyperlink\u003e\u003cw:r\u003e\u003cw:t\u003e and\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:hyperlink w:docLocation=\\\"http://www.mathworks.com/matlabcentral/cody/problems/2433-consecutive-equation-times-of-the-day\\\"\u003e\u003cw:r\u003e\u003cw:t\u003eProblem 2433\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:hyperlink\u003e\u003cw:r\u003e\u003cw:t\u003e.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\"},{\"partUri\":\"/matlab/output.xml\",\"contentType\":\"text/xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\" standalone=\\\"no\\\" ?\u003e\u003cembeddedOutputs\u003e\u003cmetaData\u003e\u003cevaluationState\u003emanual\u003c/evaluationState\u003e\u003clayoutState\u003ecode\u003c/layoutState\u003e\u003coutputStatus\u003eready\u003c/outputStatus\u003e\u003c/metaData\u003e\u003coutputArray type=\\\"array\\\"/\u003e\u003cregionArray type=\\\"array\\\"/\u003e\u003c/embeddedOutputs\u003e\"}]}"},{"id":2433,"title":"Consecutive Equation Times (of the day)","description":"Many times throughout the day can represent mathematical equations. In this problem, we focus on the largest consecutive run of equation times that include one of the four basic operations (+,-,*,/) or the power operator (^). Find the largest such consecutive run for a given range of input times (based on three-digit 12-hour times, 1:00 to 9:59). Return the first time stamp (string) and the number of consecutive points (integer, inclusive) for the maximum run (the first run if there is a tie).\r\n\r\nFor example, in the 2:07 to 2:29 time range, the answer is ['2:11' 3] since 2:10 has no equation, 2/1=1 (2:11), 2*1=2 (2:12), 2+1=3 (2:13) and 2:14 has no equation, and there are no such runs of four in that range.\r\n\r\nThis problem is related to \u003chttp://www.mathworks.com/matlabcentral/cody/problems/2431-power-times-of-the-day Problem 2431\u003e and \u003chttp://www.mathworks.com/matlabcentral/cody/problems/2432-equation-times-of-the-day  Problem 2432\u003e.","description_html":"\u003cp\u003eMany times throughout the day can represent mathematical equations. In this problem, we focus on the largest consecutive run of equation times that include one of the four basic operations (+,-,*,/) or the power operator (^). Find the largest such consecutive run for a given range of input times (based on three-digit 12-hour times, 1:00 to 9:59). Return the first time stamp (string) and the number of consecutive points (integer, inclusive) for the maximum run (the first run if there is a tie).\u003c/p\u003e\u003cp\u003eFor example, in the 2:07 to 2:29 time range, the answer is ['2:11' 3] since 2:10 has no equation, 2/1=1 (2:11), 2*1=2 (2:12), 2+1=3 (2:13) and 2:14 has no equation, and there are no such runs of four in that range.\u003c/p\u003e\u003cp\u003eThis problem is related to \u003ca href = \"http://www.mathworks.com/matlabcentral/cody/problems/2431-power-times-of-the-day\"\u003eProblem 2431\u003c/a\u003e and \u003ca href = \"http://www.mathworks.com/matlabcentral/cody/problems/2432-equation-times-of-the-day\"\u003eProblem 2432\u003c/a\u003e.\u003c/p\u003e","function_template":"function [t_s,num] = equation_times_run(times)\r\n t_s = '0:00';\r\n num = 0;\r\nend","test_suite":"%%\r\ntimes = {'1:00' '1:59'};\r\ny_correct = ['1:00' 24];\r\n[t_s,num] = equation_times_run(times);\r\nassert(isequal([t_s,num],y_correct))\r\n\r\n%%\r\ntimes = {'2:07' '2:29'};\r\ny_correct = ['2:11' 3];\r\n[t_s,num] = equation_times_run(times);\r\nassert(isequal([t_s,num],y_correct))\r\n\r\n%%\r\ntimes = {'3:03' '4:04'};\r\ny_correct = ['3:11' 4];\r\n[t_s,num] = equation_times_run(times);\r\nassert(isequal([t_s,num],y_correct))\r\n\r\n%%\r\ntimes = {'5:55' '7:11'};\r\ny_correct = ['6:15' 3];\r\n[t_s,num] = equation_times_run(times);\r\nassert(isequal([t_s,num],y_correct))\r\n\r\n%%\r\ntimes = {'7:17' '9:00'};\r\ny_correct = ['8:17' 3];\r\n[t_s,num] = equation_times_run(times);\r\nassert(isequal([t_s,num],y_correct))\r\n\r\n%%\r\ntimes = {'5:55' '9:00'};\r\ny_correct = ['6:15' 3];\r\n[t_s,num] = equation_times_run(times);\r\nassert(isequal([t_s,num],y_correct))\r\n\r\n%%\r\ntimes = {'1:00' '9:59'};\r\ny_correct = ['1:00' 24];\r\n[t_s,num] = equation_times_run(times);\r\nassert(isequal([t_s,num],y_correct))","published":true,"deleted":false,"likes_count":2,"comments_count":0,"created_by":26769,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":66,"test_suite_updated_at":null,"rescore_all_solutions":false,"group_id":45,"created_at":"2014-07-15T19:39:50.000Z","updated_at":"2026-01-15T14:27:21.000Z","published_at":"2014-07-15T19:39:50.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"relationships\":[{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/document\",\"targetMode\":\"\",\"relationshipId\":\"rId1\",\"target\":\"/matlab/document.xml\"},{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/output\",\"targetMode\":\"\",\"relationshipId\":\"rId2\",\"target\":\"/matlab/output.xml\"}],\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"relationship\":[],\"contentType\":\"application/vnd.mathworks.matlab.code.document+xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\\n\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eMany times throughout the day can represent mathematical equations. In this problem, we focus on the largest consecutive run of equation times that include one of the four basic operations (+,-,*,/) or the power operator (^). Find the largest such consecutive run for a given range of input times (based on three-digit 12-hour times, 1:00 to 9:59). Return the first time stamp (string) and the number of consecutive points (integer, inclusive) for the maximum run (the first run if there is a tie).\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eFor example, in the 2:07 to 2:29 time range, the answer is ['2:11' 3] since 2:10 has no equation, 2/1=1 (2:11), 2*1=2 (2:12), 2+1=3 (2:13) and 2:14 has no equation, and there are no such runs of four in that range.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eThis problem is related to\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:hyperlink w:docLocation=\\\"http://www.mathworks.com/matlabcentral/cody/problems/2431-power-times-of-the-day\\\"\u003e\u003cw:r\u003e\u003cw:t\u003eProblem 2431\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:hyperlink\u003e\u003cw:r\u003e\u003cw:t\u003e and\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:hyperlink w:docLocation=\\\"http://www.mathworks.com/matlabcentral/cody/problems/2432-equation-times-of-the-day\\\"\u003e\u003cw:r\u003e\u003cw:t\u003eProblem 2432\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:hyperlink\u003e\u003cw:r\u003e\u003cw:t\u003e.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\"},{\"partUri\":\"/matlab/output.xml\",\"contentType\":\"text/xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\" standalone=\\\"no\\\" ?\u003e\u003cembeddedOutputs\u003e\u003cmetaData\u003e\u003cevaluationState\u003emanual\u003c/evaluationState\u003e\u003clayoutState\u003ecode\u003c/layoutState\u003e\u003coutputStatus\u003eready\u003c/outputStatus\u003e\u003c/metaData\u003e\u003coutputArray type=\\\"array\\\"/\u003e\u003cregionArray type=\\\"array\\\"/\u003e\u003c/embeddedOutputs\u003e\"}]}"}],"problem_search":{"errors":[],"problems":[{"id":2959,"title":"Divide by 4","description":"Given the variable x as your input, divide it by four and put the result in y.","description_html":"\u003cp\u003eGiven the variable x as your input, divide it by four and put the result in y.\u003c/p\u003e","function_template":"function y = your_fcn_name(x)\r\n  y = (x/4);\r\nend","test_suite":"%%\r\nx = 1;\r\ny_correct = 1/4;\r\nassert(isequal(your_fcn_name(x),y_correct))\r\n","published":true,"deleted":false,"likes_count":11,"comments_count":19,"created_by":33997,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":1215,"test_suite_updated_at":null,"rescore_all_solutions":false,"group_id":1,"created_at":"2015-02-06T23:33:00.000Z","updated_at":"2026-03-17T15:40:46.000Z","published_at":"2015-02-06T23:33:03.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"relationships\":[{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/document\",\"relationshipId\":\"rId1\",\"target\":\"/matlab/document.xml\"},{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/output\",\"relationshipId\":\"rId2\",\"target\":\"/matlab/output.xml\"}],\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"relationship\":[],\"contentType\":\"application/vnd.mathworks.matlab.code.document+xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eGiven the variable x as your input, divide it by four and put the result in y.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\"},{\"partUri\":\"/matlab/output.xml\",\"contentType\":\"text/xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\" standalone=\\\"no\\\" ?\u003e\u003cembeddedOutputs\u003e\u003cmetaData\u003e\u003cevaluationState\u003emanual\u003c/evaluationState\u003e\u003clayoutState\u003ecode\u003c/layoutState\u003e\u003coutputStatus\u003eready\u003c/outputStatus\u003e\u003c/metaData\u003e\u003coutputArray type=\\\"array\\\"/\u003e\u003cregionArray type=\\\"array\\\"/\u003e\u003c/embeddedOutputs\u003e\"}]}"},{"id":2960,"title":"Divide by 4","description":"Given the variable x as your input, divide it by 4 and put the result in y.","description_html":"\u003cp\u003eGiven the variable x as your input, divide it by 4 and put the result in y.\u003c/p\u003e","function_template":"function y = onefourthx\r\n  y = x;\r\nend","test_suite":"%%\r\nx = 4;\r\ny= 1\r\ny_correct = 1;\r\nassert(isequal(onefourthx(x),y_correct))\r\n","published":true,"deleted":false,"likes_count":1,"comments_count":1,"created_by":33997,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":324,"test_suite_updated_at":"2015-02-06T23:56:14.000Z","rescore_all_solutions":true,"group_id":1,"created_at":"2015-02-06T23:39:32.000Z","updated_at":"2026-03-05T09:32:05.000Z","published_at":"2015-02-06T23:39:31.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"relationships\":[{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/document\",\"relationshipId\":\"rId1\",\"target\":\"/matlab/document.xml\"},{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/output\",\"relationshipId\":\"rId2\",\"target\":\"/matlab/output.xml\"}],\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"relationship\":[],\"contentType\":\"application/vnd.mathworks.matlab.code.document+xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eGiven the variable x as your input, divide it by 4 and put the result in y.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\"},{\"partUri\":\"/matlab/output.xml\",\"contentType\":\"text/xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\" standalone=\\\"no\\\" ?\u003e\u003cembeddedOutputs\u003e\u003cmetaData\u003e\u003cevaluationState\u003emanual\u003c/evaluationState\u003e\u003clayoutState\u003ecode\u003c/layoutState\u003e\u003coutputStatus\u003eready\u003c/outputStatus\u003e\u003c/metaData\u003e\u003coutputArray type=\\\"array\\\"/\u003e\u003cregionArray type=\\\"array\\\"/\u003e\u003c/embeddedOutputs\u003e\"}]}"},{"id":1435,"title":"Basics: Divide integers to get integer outputs in all cases","description":"Divide integers a and b in such a way that output y is always an integer (in ceil manner)","description_html":"\u003cp\u003eDivide integers a and b in such a way that output y is always an integer (in ceil manner)\u003c/p\u003e","function_template":"function y = divide_differently(a,b)\r\n  y = a;\r\nend","test_suite":"%%\r\na = [-2 2];b=3;\r\ny = [0 1];\r\nassert(isequal(divide_differently(a,b),y))\r\n%%\r\na = [-5 0];b=3;\r\ny = [-1 0];\r\nassert(isequal(divide_differently(a,b),y))","published":true,"deleted":false,"likes_count":2,"comments_count":0,"created_by":10792,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":137,"test_suite_updated_at":null,"rescore_all_solutions":false,"group_id":1,"created_at":"2013-04-19T18:54:31.000Z","updated_at":"2026-04-01T10:56:19.000Z","published_at":"2013-04-19T18:54:31.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"relationships\":[{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/document\",\"relationshipId\":\"rId1\",\"target\":\"/matlab/document.xml\"},{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/output\",\"relationshipId\":\"rId2\",\"target\":\"/matlab/output.xml\"}],\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"relationship\":[],\"contentType\":\"application/vnd.mathworks.matlab.code.document+xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eDivide integers a and b in such a way that output y is always an integer (in ceil manner)\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\"},{\"partUri\":\"/matlab/output.xml\",\"contentType\":\"text/xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\" standalone=\\\"no\\\" ?\u003e\u003cembeddedOutputs\u003e\u003cmetaData\u003e\u003cevaluationState\u003emanual\u003c/evaluationState\u003e\u003clayoutState\u003ecode\u003c/layoutState\u003e\u003coutputStatus\u003eready\u003c/outputStatus\u003e\u003c/metaData\u003e\u003coutputArray type=\\\"array\\\"/\u003e\u003cregionArray type=\\\"array\\\"/\u003e\u003c/embeddedOutputs\u003e\"}]}"},{"id":1833,"title":"Usage of java.math : Add, Multiply, Pow","description":"This challenge is an introduction to the wonderful word of java.math that allows unlimited precision calculations.  The primary reference sites are \u003chttp://docs.oracle.com/javase/1.5.0/docs/api/java/lang/Number.html Java Math\u003e, \u003chttp://docs.oracle.com/javase/1.5.0/docs/api/java/math/BigDecimal.html Java BigDecimal\u003e, and \u003chttp://docs.oracle.com/javase/1.5.0/docs/api/java/math/BigInteger.html Java BigInteger\u003e.\r\n\r\nThe usage of BigDecimal functions add, multiply, and pow will be tested.\r\n\r\nJava Math tutorial: (Simplified summary that is believed correct)\r\n\r\n  vd-decimal value, vstr-string, vi-integer value \r\n  xBD=java.math.BigDecimal(vd);  % valid vd,vstr,vi creates xBD a BigDecimal variable\r\n  import java.math.*;  % simplifies statements\r\n  xBD=BigDecimal(vstr);\r\n  x2pwrBD=xBD.pow(vi); % Invalid: vd,vstr,BD\r\n  xplusyBD=xBD.add(BigDecimal(y)); % add input requires BD type\r\n  xmultiplyzBD=xBD.multiply(BigDecimal(z));  % multiply input requires BD type\r\n  \r\n  To convert java to string of unlimited length can be achieved via java toString or Matlab char\r\n  \r\n  xstr=toString(xBD)  or xstr=char(xBD) \r\n\r\n*Input:* X,Y, function_case  [X,Y double or str, function 1:X+Y, 2:X*Y, 3: X^Y(double)\r\n\r\n*Output:* z  (char variable)\r\n\r\n*Future Challenges:*\r\n\r\n  1. nchoosek_large (full precision)\r\n  2. Next Prime\r\n  3. factor_large\r\n\r\n4. \u003chttp://www.mathworks.com/matlabcentral/cody/problems/1854-factorial-unlimited-size-java-math Factorial\u003e","description_html":"\u003cp\u003eThis challenge is an introduction to the wonderful word of java.math that allows unlimited precision calculations.  The primary reference sites are \u003ca href = \"http://docs.oracle.com/javase/1.5.0/docs/api/java/lang/Number.html\"\u003eJava Math\u003c/a\u003e, \u003ca href = \"http://docs.oracle.com/javase/1.5.0/docs/api/java/math/BigDecimal.html\"\u003eJava BigDecimal\u003c/a\u003e, and \u003ca href = \"http://docs.oracle.com/javase/1.5.0/docs/api/java/math/BigInteger.html\"\u003eJava BigInteger\u003c/a\u003e.\u003c/p\u003e\u003cp\u003eThe usage of BigDecimal functions add, multiply, and pow will be tested.\u003c/p\u003e\u003cp\u003eJava Math tutorial: (Simplified summary that is believed correct)\u003c/p\u003e\u003cpre class=\"language-matlab\"\u003evd-decimal value, vstr-string, vi-integer value \r\nxBD=java.math.BigDecimal(vd);  % valid vd,vstr,vi creates xBD a BigDecimal variable\r\nimport java.math.*;  % simplifies statements\r\nxBD=BigDecimal(vstr);\r\nx2pwrBD=xBD.pow(vi); % Invalid: vd,vstr,BD\r\nxplusyBD=xBD.add(BigDecimal(y)); % add input requires BD type\r\nxmultiplyzBD=xBD.multiply(BigDecimal(z));  % multiply input requires BD type\r\n\u003c/pre\u003e\u003cpre class=\"language-matlab\"\u003eTo convert java to string of unlimited length can be achieved via java toString or Matlab char\r\n\u003c/pre\u003e\u003cpre class=\"language-matlab\"\u003exstr=toString(xBD)  or xstr=char(xBD) \r\n\u003c/pre\u003e\u003cp\u003e\u003cb\u003eInput:\u003c/b\u003e X,Y, function_case  [X,Y double or str, function 1:X+Y, 2:X*Y, 3: X^Y(double)\u003c/p\u003e\u003cp\u003e\u003cb\u003eOutput:\u003c/b\u003e z  (char variable)\u003c/p\u003e\u003cp\u003e\u003cb\u003eFuture Challenges:\u003c/b\u003e\u003c/p\u003e\u003cpre class=\"language-matlab\"\u003e1. nchoosek_large (full precision)\r\n2. Next Prime\r\n3. factor_large\r\n\u003c/pre\u003e\u003cp\u003e4. \u003ca href = \"http://www.mathworks.com/matlabcentral/cody/problems/1854-factorial-unlimited-size-java-math\"\u003eFactorial\u003c/a\u003e\u003c/p\u003e","function_template":"function zstr=java_math(x,y,select)\r\n import java.math.*\r\n\r\n switch select\r\n    case 1 % add x+y\r\n     zBD=x+y;\r\n    case 2 % multiply  x*y\r\n     zBD=x*y;\r\n    case 3 % power  x^y\r\n     zBD=x^y;\r\n     \r\n end\r\n zstr=char(zBD);\r\n\r\nend","test_suite":"%%\r\nx=2;\r\ny=64;\r\n% power\r\nzstr=java_math(x,y,3);\r\nassert(strcmp(zstr,'18446744073709551616'),sprintf('zstr=%s\\n',zstr))\r\n%%\r\nxstr='18446744073709551615';\r\ny=3;\r\n%Add\r\nzstr=java_math(xstr,y,1);\r\nassert(strcmp(zstr,'18446744073709551618'),sprintf('zstr=%s\\n',zstr))\r\n%%\r\nx=2^53;  % largest eps==1 double\r\ny=2^11;\r\n%Multiply\r\nzstr=java_math(x,y,2);\r\nassert(strcmp(zstr,'18446744073709551616'),sprintf('zstr=%s\\n',zstr))\r\n%%\r\nx=2^53;  % largest valid double\r\ny=2^12;\r\n% Multiply\r\nzstr=java_math(x,y,2);\r\nassert(strcmp(zstr,'36893488147419103232'),sprintf('zstr=%s\\n',zstr))\r\n%%\r\nx=randi(10);\r\ny=randi(100);\r\nzstr=java_math(x,y,1);\r\nassert(strcmp(zstr,num2str(x+y)),sprintf('x=%2i y=%3i x+y=%5i zstr=%s\\n',x,y,x+y,zstr))\r\n%%\r\nx=randi(10);\r\ny=randi(100);\r\nzstr=java_math(x,y,2);\r\nassert(strcmp(zstr,num2str(x*y)),sprintf('x=%2i y=%3i x*y=%5i zstr=%s\\n',x,y,x*y,zstr))\r\n%%\r\nx=randi(20);\r\ny=randi(5);\r\nzstr=java_math(x,y,3);\r\nassert(strcmp(zstr,num2str(x^y)),sprintf('x=%2i y=%3i x^y=%8i zstr=%s\\n',x,y,x^y,zstr))\r\n\r\n\r\n","published":true,"deleted":false,"likes_count":4,"comments_count":3,"created_by":3097,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":37,"test_suite_updated_at":null,"rescore_all_solutions":false,"group_id":1,"created_at":"2013-08-18T17:42:26.000Z","updated_at":"2025-12-10T01:06:03.000Z","published_at":"2013-08-18T19:02:27.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"relationships\":[{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/document\",\"targetMode\":\"\",\"relationshipId\":\"rId1\",\"target\":\"/matlab/document.xml\"},{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/output\",\"targetMode\":\"\",\"relationshipId\":\"rId2\",\"target\":\"/matlab/output.xml\"}],\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"relationship\":[],\"contentType\":\"application/vnd.mathworks.matlab.code.document+xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\\n\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eThis challenge is an introduction to the wonderful word of java.math that allows unlimited precision calculations. The primary reference sites are\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:hyperlink w:docLocation=\\\"http://docs.oracle.com/javase/1.5.0/docs/api/java/lang/Number.html\\\"\u003e\u003cw:r\u003e\u003cw:t\u003eJava Math\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:hyperlink\u003e\u003cw:r\u003e\u003cw:t\u003e,\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:hyperlink w:docLocation=\\\"http://docs.oracle.com/javase/1.5.0/docs/api/java/math/BigDecimal.html\\\"\u003e\u003cw:r\u003e\u003cw:t\u003eJava BigDecimal\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:hyperlink\u003e\u003cw:r\u003e\u003cw:t\u003e, and\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:hyperlink w:docLocation=\\\"http://docs.oracle.com/javase/1.5.0/docs/api/java/math/BigInteger.html\\\"\u003e\u003cw:r\u003e\u003cw:t\u003eJava BigInteger\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:hyperlink\u003e\u003cw:r\u003e\u003cw:t\u003e.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eThe usage of BigDecimal functions add, multiply, and pow will be tested.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eJava Math tutorial: (Simplified summary that is believed correct)\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"code\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003e\u003c![CDATA[vd-decimal value, vstr-string, vi-integer value \\nxBD=java.math.BigDecimal(vd);  % valid vd,vstr,vi creates xBD a BigDecimal variable\\nimport java.math.*;  % simplifies statements\\nxBD=BigDecimal(vstr);\\nx2pwrBD=xBD.pow(vi); % Invalid: vd,vstr,BD\\nxplusyBD=xBD.add(BigDecimal(y)); % add input requires BD type\\nxmultiplyzBD=xBD.multiply(BigDecimal(z));  % multiply input requires BD type\\n\\nTo convert java to string of unlimited length can be achieved via java toString or Matlab char\\n\\nxstr=toString(xBD)  or xstr=char(xBD)]]\u003e\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:b/\u003e\u003c/w:rPr\u003e\u003cw:t\u003eInput:\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e X,Y, function_case [X,Y double or str, function 1:X+Y, 2:X*Y, 3: X^Y(double)\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:b/\u003e\u003c/w:rPr\u003e\u003cw:t\u003eOutput:\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e z (char variable)\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:b/\u003e\u003c/w:rPr\u003e\u003cw:t\u003eFuture Challenges:\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"code\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003e\u003c![CDATA[1. nchoosek_large (full precision)\\n2. Next Prime\\n3. factor_large]]\u003e\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003e4.\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:hyperlink w:docLocation=\\\"http://www.mathworks.com/matlabcentral/cody/problems/1854-factorial-unlimited-size-java-math\\\"\u003e\u003cw:r\u003e\u003cw:t\u003eFactorial\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:hyperlink\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\"},{\"partUri\":\"/matlab/output.xml\",\"contentType\":\"text/xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\" standalone=\\\"no\\\" ?\u003e\u003cembeddedOutputs\u003e\u003cmetaData\u003e\u003cevaluationState\u003emanual\u003c/evaluationState\u003e\u003clayoutState\u003ecode\u003c/layoutState\u003e\u003coutputStatus\u003eready\u003c/outputStatus\u003e\u003c/metaData\u003e\u003coutputArray type=\\\"array\\\"/\u003e\u003cregionArray type=\\\"array\\\"/\u003e\u003c/embeddedOutputs\u003e\"}]}"},{"id":2230,"title":"Back to basics - array operations","description":"Without performing actual arithmetic operations on arrays, return feasibility of operation as true or false. True if given operation can be performed on given matrices, else false.\r\nExample\r\n Operation = 'Add'\r\n Matrices are:\r\n  a = magic(3);\r\n  b = [2 2; 2 2; 2 2]\r\nResult: false, since size of a and b should be same to perform \"Add\" operation.","description_html":"\u003cdiv style = \"text-align: start; line-height: 20.4333px; min-height: 0px; white-space: normal; color: rgb(0, 0, 0); font-family: Menlo, Monaco, Consolas, monospace; font-style: normal; font-size: 14px; font-weight: 400; text-decoration: rgb(0, 0, 0); white-space: normal; \"\u003e\u003cdiv style=\"block-size: 194.733px; display: block; min-width: 0px; padding-block-start: 0px; padding-top: 0px; perspective-origin: 407px 97.3667px; transform-origin: 407px 97.3667px; vertical-align: baseline; \"\u003e\u003cdiv style=\"block-size: 42px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 21px; text-align: left; transform-origin: 384px 21px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 369.5px 8px; transform-origin: 369.5px 8px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003eWithout performing actual arithmetic operations on arrays, return feasibility of operation as true or false. True if given operation can be performed on given matrices, else false.\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 21px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 10.5px; text-align: left; transform-origin: 384px 10.5px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 26.5px 8px; transform-origin: 26.5px 8px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003eExample\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"background-color: rgb(247, 247, 247); block-size: 81.7333px; border-bottom-left-radius: 4px; border-bottom-right-radius: 4px; border-end-end-radius: 4px; border-end-start-radius: 4px; border-start-end-radius: 4px; border-start-start-radius: 4px; border-top-left-radius: 4px; border-top-right-radius: 4px; margin-block-end: 10px; margin-block-start: 10px; margin-bottom: 10px; margin-inline-end: 3px; margin-inline-start: 3px; margin-left: 3px; margin-right: 3px; margin-top: 10px; perspective-origin: 404px 40.8667px; transform-origin: 404px 40.8667px; margin-left: 3px; margin-top: 10px; margin-bottom: 10px; margin-right: 3px; \"\u003e\u003cdiv style=\"background-color: rgba(0, 0, 0, 0); block-size: 20.4333px; border-bottom-left-radius: 0px; border-bottom-right-radius: 0px; border-end-end-radius: 0px; border-end-start-radius: 0px; border-inline-end-color: rgb(233, 233, 233); border-inline-end-style: solid; border-inline-end-width: 1px; border-inline-start-color: rgb(233, 233, 233); border-inline-start-style: solid; border-inline-start-width: 1px; border-left-color: rgb(233, 233, 233); border-left-style: solid; border-left-width: 1px; border-right-color: rgb(233, 233, 233); border-right-style: solid; border-right-width: 1px; border-start-end-radius: 0px; border-start-start-radius: 0px; border-top-left-radius: 0px; border-top-right-radius: 0px; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; min-block-size: 18px; min-height: 18px; padding-inline-start: 4px; padding-left: 4px; perspective-origin: 404px 10.2167px; transform-origin: 404px 10.2167px; white-space: nowrap; \"\u003e\u003cspan style=\"block-size: auto; border-inline-end-color: rgb(0, 0, 0); border-inline-end-style: none; border-inline-end-width: 0px; border-inline-start-color: rgb(0, 0, 0); border-inline-start-style: none; border-inline-start-width: 0px; border-left-color: rgb(0, 0, 0); border-left-style: none; border-left-width: 0px; border-right-color: rgb(0, 0, 0); border-right-style: none; border-right-width: 0px; display: inline; margin-inline-end: 45px; margin-right: 45px; min-block-size: 0px; min-height: 0px; padding-inline-start: 0px; padding-left: 0px; perspective-origin: 72px 8.5px; tab-size: 4; transform-origin: 72px 8.5px; unicode-bidi: normal; white-space: pre; margin-right: 45px; \"\u003e\u003cspan style=\"margin-inline-end: 0px; margin-right: 0px; perspective-origin: 52px 8.5px; transform-origin: 52px 8.5px; \"\u003e Operation = \u003c/span\u003e\u003cspan style=\"border-block-end-color: rgb(170, 4, 249); border-block-start-color: rgb(170, 4, 249); border-bottom-color: rgb(170, 4, 249); border-inline-end-color: rgb(170, 4, 249); border-inline-start-color: rgb(170, 4, 249); border-left-color: rgb(170, 4, 249); border-right-color: rgb(170, 4, 249); border-top-color: rgb(170, 4, 249); caret-color: rgb(170, 4, 249); color: rgb(170, 4, 249); column-rule-color: rgb(170, 4, 249); margin-inline-end: 0px; margin-right: 0px; outline-color: rgb(170, 4, 249); perspective-origin: 20px 8.5px; text-decoration-color: rgb(170, 4, 249); text-emphasis-color: rgb(170, 4, 249); transform-origin: 20px 8.5px; \"\u003e'Add'\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"background-color: rgba(0, 0, 0, 0); block-size: 20.4333px; border-bottom-left-radius: 0px; border-bottom-right-radius: 0px; border-end-end-radius: 0px; border-end-start-radius: 0px; border-inline-end-color: rgb(233, 233, 233); border-inline-end-style: solid; border-inline-end-width: 1px; border-inline-start-color: rgb(233, 233, 233); border-inline-start-style: solid; border-inline-start-width: 1px; border-left-color: rgb(233, 233, 233); border-left-style: solid; border-left-width: 1px; border-right-color: rgb(233, 233, 233); border-right-style: solid; border-right-width: 1px; border-start-end-radius: 0px; border-start-start-radius: 0px; border-top-left-radius: 0px; border-top-right-radius: 0px; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; min-block-size: 18px; min-height: 18px; padding-inline-start: 4px; padding-left: 4px; perspective-origin: 404px 10.2167px; transform-origin: 404px 10.2167px; white-space: nowrap; \"\u003e\u003cspan style=\"block-size: auto; border-inline-end-color: rgb(0, 0, 0); border-inline-end-style: none; border-inline-end-width: 0px; border-inline-start-color: rgb(0, 0, 0); border-inline-start-style: none; border-inline-start-width: 0px; border-left-color: rgb(0, 0, 0); border-left-style: none; border-left-width: 0px; border-right-color: rgb(0, 0, 0); border-right-style: none; border-right-width: 0px; display: inline; margin-inline-end: 45px; margin-right: 45px; min-block-size: 0px; min-height: 0px; padding-inline-start: 0px; padding-left: 0px; perspective-origin: 56px 8.5px; tab-size: 4; transform-origin: 56px 8.5px; unicode-bidi: normal; white-space: pre; margin-right: 45px; \"\u003e\u003cspan style=\"margin-inline-end: 0px; margin-right: 0px; perspective-origin: 40px 8.5px; transform-origin: 40px 8.5px; \"\u003e Matrices \u003c/span\u003e\u003cspan style=\"border-block-end-color: rgb(170, 4, 249); border-block-start-color: rgb(170, 4, 249); border-bottom-color: rgb(170, 4, 249); border-inline-end-color: rgb(170, 4, 249); border-inline-start-color: rgb(170, 4, 249); border-left-color: rgb(170, 4, 249); border-right-color: rgb(170, 4, 249); border-top-color: rgb(170, 4, 249); caret-color: rgb(170, 4, 249); color: rgb(170, 4, 249); column-rule-color: rgb(170, 4, 249); margin-inline-end: 0px; margin-right: 0px; outline-color: rgb(170, 4, 249); perspective-origin: 16px 8.5px; text-decoration-color: rgb(170, 4, 249); text-emphasis-color: rgb(170, 4, 249); transform-origin: 16px 8.5px; \"\u003eare:\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"background-color: rgba(0, 0, 0, 0); block-size: 20.4333px; border-bottom-left-radius: 0px; border-bottom-right-radius: 0px; border-end-end-radius: 0px; border-end-start-radius: 0px; border-inline-end-color: rgb(233, 233, 233); border-inline-end-style: solid; border-inline-end-width: 1px; border-inline-start-color: rgb(233, 233, 233); border-inline-start-style: solid; border-inline-start-width: 1px; border-left-color: rgb(233, 233, 233); border-left-style: solid; border-left-width: 1px; border-right-color: rgb(233, 233, 233); border-right-style: solid; border-right-width: 1px; border-start-end-radius: 0px; border-start-start-radius: 0px; border-top-left-radius: 0px; border-top-right-radius: 0px; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; min-block-size: 18px; min-height: 18px; padding-inline-start: 4px; padding-left: 4px; perspective-origin: 404px 10.2167px; transform-origin: 404px 10.2167px; white-space: nowrap; \"\u003e\u003cspan style=\"block-size: auto; border-inline-end-color: rgb(0, 0, 0); border-inline-end-style: none; border-inline-end-width: 0px; border-inline-start-color: rgb(0, 0, 0); border-inline-start-style: none; border-inline-start-width: 0px; border-left-color: rgb(0, 0, 0); border-left-style: none; border-left-width: 0px; border-right-color: rgb(0, 0, 0); border-right-style: none; border-right-width: 0px; display: inline; margin-inline-end: 45px; margin-right: 45px; min-block-size: 0px; min-height: 0px; padding-inline-start: 0px; padding-left: 0px; perspective-origin: 60px 8.5px; tab-size: 4; transform-origin: 60px 8.5px; unicode-bidi: normal; white-space: pre; margin-right: 45px; \"\u003e\u003cspan style=\"margin-inline-end: 0px; margin-right: 0px; \"\u003e  a = magic(3);\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"background-color: rgba(0, 0, 0, 0); block-size: 20.4333px; border-bottom-left-radius: 0px; border-bottom-right-radius: 0px; border-end-end-radius: 0px; border-end-start-radius: 0px; border-inline-end-color: rgb(233, 233, 233); border-inline-end-style: solid; border-inline-end-width: 1px; border-inline-start-color: rgb(233, 233, 233); border-inline-start-style: solid; border-inline-start-width: 1px; border-left-color: rgb(233, 233, 233); border-left-style: solid; border-left-width: 1px; border-right-color: rgb(233, 233, 233); border-right-style: solid; border-right-width: 1px; border-start-end-radius: 0px; border-start-start-radius: 0px; border-top-left-radius: 0px; border-top-right-radius: 0px; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; min-block-size: 18px; min-height: 18px; padding-inline-start: 4px; padding-left: 4px; perspective-origin: 404px 10.2167px; transform-origin: 404px 10.2167px; white-space: nowrap; \"\u003e\u003cspan style=\"block-size: auto; border-inline-end-color: rgb(0, 0, 0); border-inline-end-style: none; border-inline-end-width: 0px; border-inline-start-color: rgb(0, 0, 0); border-inline-start-style: none; border-inline-start-width: 0px; border-left-color: rgb(0, 0, 0); border-left-style: none; border-left-width: 0px; border-right-color: rgb(0, 0, 0); border-right-style: none; border-right-width: 0px; display: inline; margin-inline-end: 45px; margin-right: 45px; min-block-size: 0px; min-height: 0px; padding-inline-start: 0px; padding-left: 0px; perspective-origin: 84px 8.5px; tab-size: 4; transform-origin: 84px 8.5px; unicode-bidi: normal; white-space: pre; margin-right: 45px; \"\u003e\u003cspan style=\"margin-inline-end: 0px; margin-right: 0px; \"\u003e  b = [2 2; 2 2; 2 2]\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 21px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 10px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 10px; perspective-origin: 384px 10.5px; text-align: left; transform-origin: 384px 10.5px; white-space: pre-wrap; margin-left: 4px; margin-top: 10px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 247.5px 8px; transform-origin: 247.5px 8px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003eResult: false, since size of a and b should be same to perform \"Add\" operation.\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003c/div\u003e\u003c/div\u003e","function_template":"function y = ArrayOperation(a,b,operation)\r\n  y = true;\r\nend","test_suite":"%%\r\nx = magic(3);\r\ny = eye(3);\r\noperation = 'Add';\r\ny_correct = true;\r\nassert(isequal(ArrayOperation(x,y,operation),y_correct))\r\n\r\n%%\r\nx = magic(3);\r\ny = eye(2);\r\noperation = 'Add';\r\ny_correct = false;\r\nassert(isequal(ArrayOperation(x,y,operation),y_correct))\r\n\r\n%%\r\nx = magic(3);\r\ny = repmat(3,3,3);\r\noperation = 'Multiply';\r\ny_correct = true;\r\nassert(isequal(ArrayOperation(x,y,operation),y_correct))\r\n\r\n%%\r\nx = magic(3);\r\ny = repmat(3,3,2);\r\noperation = 'Multiply';\r\ny_correct = true;\r\nassert(isequal(ArrayOperation(x,y,operation),y_correct))\r\n\r\n%%\r\nx = 3;\r\ny = repmat(3,3,2);\r\noperation = 'Add';\r\ny_correct = true;\r\nassert(isequal(ArrayOperation(x,y,operation),y_correct))\r\n\r\n%%\r\nx = 3;\r\ny = repmat(3,3,2);\r\noperation = 'Subtract';\r\ny_correct = true;\r\nassert(isequal(ArrayOperation(x,y,operation),y_correct))\r\n\r\n%%\r\nx = 3;\r\ny = repmat(3,3,2);\r\noperation = 'Divide';\r\ny_correct = false;\r\nassert(isequal(ArrayOperation(x,y,operation),y_correct))\r\n\r\n%%\r\nx = 3;\r\ny = repmat(3,3,2);\r\noperation = 'Divide';\r\ny_correct = true;\r\nassert(isequal(ArrayOperation(y,x,operation),y_correct))\r\n\r\n%%\r\nx = ones(3,2);\r\ny = repmat(3,3,2);\r\noperation = 'Divide';\r\ny_correct = true;\r\nassert(isequal(ArrayOperation(x,y,operation),y_correct))\r\n\r\n%%\r\nx = 3;\r\ny = ones(5,7);\r\noperation = 'Multiply';\r\ny_correct = true;\r\nassert(isequal(ArrayOperation(x,y,operation),y_correct))\r\n\r\n%%\r\nx = ones(3,3);\r\ny = repmat(3,3,2);\r\noperation = 'Divide';\r\ny_correct = false;\r\nassert(isequal(ArrayOperation(x,y,operation),y_correct))","published":true,"deleted":false,"likes_count":1,"comments_count":2,"created_by":16381,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":53,"test_suite_updated_at":"2022-02-22T05:49:00.000Z","rescore_all_solutions":false,"group_id":1,"created_at":"2014-03-03T22:31:03.000Z","updated_at":"2025-12-04T17:14:15.000Z","published_at":"2014-03-03T22:33:40.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"contentType\":\"application/vnd.mathworks.matlab.code.document+xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eWithout performing actual arithmetic operations on arrays, return feasibility of operation as true or false. True if given operation can be performed on given matrices, else false.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eExample\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"code\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003e\u003c![CDATA[ Operation = 'Add'\\n Matrices are:\\n  a = magic(3);\\n  b = [2 2; 2 2; 2 2]]]\u003e\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eResult: false, since size of a and b should be same to perform \\\"Add\\\" operation.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\",\"relationship\":null}],\"relationships\":[{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/document\",\"target\":\"/matlab/document.xml\",\"relationshipId\":\"rId1\"}]}"},{"id":2432,"title":"Equation Times (of the day)","description":"Many times throughout the day can represent mathematical equations. In this problem, we focus on times that include the four basic operations (+,-,*,/). For example, 6:17 can be written as 6=1+7. Write a function that determines if the given time (restricted to three digits in 12-hour time, 1:00 to 9:59) is an equation time, and if so, which basic operation it uses. There are also four types of equations that are categorized here, and a given time can fit more than one category:\r\n\r\n - equation written forward, \"=\" doesn't coincide with \":\" --\u003e add 1 to output (e.g., 2:35, 2+3=5)\r\n\r\n - equation written forward, \"=\" does coincide with \":\" -- \u003e add 100 to output (e.g., 2:53, 2=5-3)\r\n\r\n - equation written backward, \"=\" doesn't coincide with \":\" --\u003e add 10 to output (e.g., 3:26, 6=2*3)\r\n\r\n - equation written backward, \"=\" does coincide with \":\" --\u003e add 1000 to output (e.g., 4:28, 8/2=4)\r\n\r\nNote that some of these combinations are tied to each other due to the commutative nature of + and * and the inverse relation of +,- and **,/. The output should be a 4x2 matrix with 0s or 1s in the first column dependent on whether each operation (+,-,*,/) is applicable to a given time and the totals in the second column. Examples include: \r\n\r\n4:22 | out = [1 1100; 1 1; 1 1100; 1 1]; since 4=2+2, 2+2=4; 4-2=2; 4=2*2, 2*2=4; 4/2=2.\r\n\r\n5:15 | out = [0 0; 0 0; 1 1111; 1 1001]; since 5*1=5, 5=1*5, 5*1=5, 5=1*5; 5/1=5, 5/1=5.\r\n\r\nThis problem is related to \u003chttp://www.mathworks.com/matlabcentral/cody/problems/2431-power-times-of-the-day Problem 2431\u003e and \u003chttp://www.mathworks.com/matlabcentral/cody/problems/2433-consecutive-equation-times-of-the-day Problem 2433\u003e.","description_html":"\u003cp\u003eMany times throughout the day can represent mathematical equations. In this problem, we focus on times that include the four basic operations (+,-,*,/). For example, 6:17 can be written as 6=1+7. Write a function that determines if the given time (restricted to three digits in 12-hour time, 1:00 to 9:59) is an equation time, and if so, which basic operation it uses. There are also four types of equations that are categorized here, and a given time can fit more than one category:\u003c/p\u003e\u003cpre\u003e - equation written forward, \"=\" doesn't coincide with \":\" --\u0026gt; add 1 to output (e.g., 2:35, 2+3=5)\u003c/pre\u003e\u003cpre\u003e - equation written forward, \"=\" does coincide with \":\" -- \u0026gt; add 100 to output (e.g., 2:53, 2=5-3)\u003c/pre\u003e\u003cpre\u003e - equation written backward, \"=\" doesn't coincide with \":\" --\u0026gt; add 10 to output (e.g., 3:26, 6=2*3)\u003c/pre\u003e\u003cpre\u003e - equation written backward, \"=\" does coincide with \":\" --\u0026gt; add 1000 to output (e.g., 4:28, 8/2=4)\u003c/pre\u003e\u003cp\u003eNote that some of these combinations are tied to each other due to the commutative nature of + and * and the inverse relation of +,- and ,/. The output should be a 4x2 matrix with 0s or 1s in the first column dependent on whether each operation (+,-,*,/) is applicable to a given time and the totals in the second column. Examples include:\u003c/p\u003e\u003cp\u003e4:22 | out = [1 1100; 1 1; 1 1100; 1 1]; since 4=2+2, 2+2=4; 4-2=2; 4=2*2, 2*2=4; 4/2=2.\u003c/p\u003e\u003cp\u003e5:15 | out = [0 0; 0 0; 1 1111; 1 1001]; since 5*1=5, 5=1*5, 5*1=5, 5=1*5; 5/1=5, 5/1=5.\u003c/p\u003e\u003cp\u003eThis problem is related to \u003ca href = \"http://www.mathworks.com/matlabcentral/cody/problems/2431-power-times-of-the-day\"\u003eProblem 2431\u003c/a\u003e and \u003ca href = \"http://www.mathworks.com/matlabcentral/cody/problems/2433-consecutive-equation-times-of-the-day\"\u003eProblem 2433\u003c/a\u003e.\u003c/p\u003e","function_template":"function out = equation_time(time)\r\n out = 0;\r\nend","test_suite":"%%\r\ntime = '4:22';\r\ny_correct = [1 1100;\r\n\t1 1;\r\n\t1 1100;\r\n\t1 1];\r\nassert(isequal(equation_time(time),y_correct))\r\n\r\n%%\r\ntime = '2:38';\r\ny_correct = zeros(4,2);\r\nassert(isequal(equation_time(time),y_correct))\r\n\r\n%%\r\ntime = '5:15';\r\ny_correct = [0 0;\r\n\t0 0;\r\n\t1 1111;\r\n \t1 1001];\r\nassert(isequal(equation_time(time),y_correct))\r\n\r\n%%\r\ntime = '1:23';\r\ny_correct = [1 11;\r\n\t1 1000;\r\n\t0 0;\r\n \t0 0];\r\nassert(isequal(equation_time(time),y_correct))\r\n\r\n%%\r\ntime = '1:02';\r\ny_correct = zeros(4,2);\r\nassert(isequal(equation_time(time),y_correct))\r\n\r\n%%\r\ntime = '1:11';\r\ny_correct = [0 0;\r\n\t0 0;\r\n\t1 1111;\r\n \t1 1111];\r\nassert(isequal(equation_time(time),y_correct))\r\n\r\n%%\r\ntime = '2:11';\r\ny_correct = [1 1100;\r\n\t1 1;\r\n\t0 0;\r\n \t0 0];\r\nassert(isequal(equation_time(time),y_correct))","published":true,"deleted":false,"likes_count":3,"comments_count":0,"created_by":26769,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":79,"test_suite_updated_at":null,"rescore_all_solutions":false,"group_id":45,"created_at":"2014-07-15T18:39:02.000Z","updated_at":"2026-01-15T14:29:10.000Z","published_at":"2014-07-15T18:39:02.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"relationships\":[{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/document\",\"targetMode\":\"\",\"relationshipId\":\"rId1\",\"target\":\"/matlab/document.xml\"},{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/output\",\"targetMode\":\"\",\"relationshipId\":\"rId2\",\"target\":\"/matlab/output.xml\"}],\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"relationship\":[],\"contentType\":\"application/vnd.mathworks.matlab.code.document+xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\\n\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eMany times throughout the day can represent mathematical equations. In this problem, we focus on times that include the four basic operations (+,-,*,/). For example, 6:17 can be written as 6=1+7. Write a function that determines if the given time (restricted to three digits in 12-hour time, 1:00 to 9:59) is an equation time, and if so, which basic operation it uses. There are also four types of equations that are categorized here, and a given time can fit more than one category:\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"code\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003e\u003c![CDATA[ - equation written forward, \\\"=\\\" doesn't coincide with \\\":\\\" --\u003e add 1 to output (e.g., 2:35, 2+3=5)\\n\\n - equation written forward, \\\"=\\\" does coincide with \\\":\\\" -- \u003e add 100 to output (e.g., 2:53, 2=5-3)\\n\\n - equation written backward, \\\"=\\\" doesn't coincide with \\\":\\\" --\u003e add 10 to output (e.g., 3:26, 6=2*3)\\n\\n - equation written backward, \\\"=\\\" does coincide with \\\":\\\" --\u003e add 1000 to output (e.g., 4:28, 8/2=4)]]\u003e\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eNote that some of these combinations are tied to each other due to the commutative nature of + and * and the inverse relation of +,- and ,/. The output should be a 4x2 matrix with 0s or 1s in the first column dependent on whether each operation (+,-,*,/) is applicable to a given time and the totals in the second column. Examples include:\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003e4:22 | out = [1 1100; 1 1; 1 1100; 1 1]; since 4=2+2, 2+2=4; 4-2=2; 4=2*2, 2*2=4; 4/2=2.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003e5:15 | out = [0 0; 0 0; 1 1111; 1 1001]; since 5*1=5, 5=1*5, 5*1=5, 5=1*5; 5/1=5, 5/1=5.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eThis problem is related to\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:hyperlink w:docLocation=\\\"http://www.mathworks.com/matlabcentral/cody/problems/2431-power-times-of-the-day\\\"\u003e\u003cw:r\u003e\u003cw:t\u003eProblem 2431\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:hyperlink\u003e\u003cw:r\u003e\u003cw:t\u003e and\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:hyperlink w:docLocation=\\\"http://www.mathworks.com/matlabcentral/cody/problems/2433-consecutive-equation-times-of-the-day\\\"\u003e\u003cw:r\u003e\u003cw:t\u003eProblem 2433\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:hyperlink\u003e\u003cw:r\u003e\u003cw:t\u003e.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\"},{\"partUri\":\"/matlab/output.xml\",\"contentType\":\"text/xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\" standalone=\\\"no\\\" ?\u003e\u003cembeddedOutputs\u003e\u003cmetaData\u003e\u003cevaluationState\u003emanual\u003c/evaluationState\u003e\u003clayoutState\u003ecode\u003c/layoutState\u003e\u003coutputStatus\u003eready\u003c/outputStatus\u003e\u003c/metaData\u003e\u003coutputArray type=\\\"array\\\"/\u003e\u003cregionArray type=\\\"array\\\"/\u003e\u003c/embeddedOutputs\u003e\"}]}"},{"id":2433,"title":"Consecutive Equation Times (of the day)","description":"Many times throughout the day can represent mathematical equations. In this problem, we focus on the largest consecutive run of equation times that include one of the four basic operations (+,-,*,/) or the power operator (^). Find the largest such consecutive run for a given range of input times (based on three-digit 12-hour times, 1:00 to 9:59). Return the first time stamp (string) and the number of consecutive points (integer, inclusive) for the maximum run (the first run if there is a tie).\r\n\r\nFor example, in the 2:07 to 2:29 time range, the answer is ['2:11' 3] since 2:10 has no equation, 2/1=1 (2:11), 2*1=2 (2:12), 2+1=3 (2:13) and 2:14 has no equation, and there are no such runs of four in that range.\r\n\r\nThis problem is related to \u003chttp://www.mathworks.com/matlabcentral/cody/problems/2431-power-times-of-the-day Problem 2431\u003e and \u003chttp://www.mathworks.com/matlabcentral/cody/problems/2432-equation-times-of-the-day  Problem 2432\u003e.","description_html":"\u003cp\u003eMany times throughout the day can represent mathematical equations. In this problem, we focus on the largest consecutive run of equation times that include one of the four basic operations (+,-,*,/) or the power operator (^). Find the largest such consecutive run for a given range of input times (based on three-digit 12-hour times, 1:00 to 9:59). Return the first time stamp (string) and the number of consecutive points (integer, inclusive) for the maximum run (the first run if there is a tie).\u003c/p\u003e\u003cp\u003eFor example, in the 2:07 to 2:29 time range, the answer is ['2:11' 3] since 2:10 has no equation, 2/1=1 (2:11), 2*1=2 (2:12), 2+1=3 (2:13) and 2:14 has no equation, and there are no such runs of four in that range.\u003c/p\u003e\u003cp\u003eThis problem is related to \u003ca href = \"http://www.mathworks.com/matlabcentral/cody/problems/2431-power-times-of-the-day\"\u003eProblem 2431\u003c/a\u003e and \u003ca href = \"http://www.mathworks.com/matlabcentral/cody/problems/2432-equation-times-of-the-day\"\u003eProblem 2432\u003c/a\u003e.\u003c/p\u003e","function_template":"function [t_s,num] = equation_times_run(times)\r\n t_s = '0:00';\r\n num = 0;\r\nend","test_suite":"%%\r\ntimes = {'1:00' '1:59'};\r\ny_correct = ['1:00' 24];\r\n[t_s,num] = equation_times_run(times);\r\nassert(isequal([t_s,num],y_correct))\r\n\r\n%%\r\ntimes = {'2:07' '2:29'};\r\ny_correct = ['2:11' 3];\r\n[t_s,num] = equation_times_run(times);\r\nassert(isequal([t_s,num],y_correct))\r\n\r\n%%\r\ntimes = {'3:03' '4:04'};\r\ny_correct = ['3:11' 4];\r\n[t_s,num] = equation_times_run(times);\r\nassert(isequal([t_s,num],y_correct))\r\n\r\n%%\r\ntimes = {'5:55' '7:11'};\r\ny_correct = ['6:15' 3];\r\n[t_s,num] = equation_times_run(times);\r\nassert(isequal([t_s,num],y_correct))\r\n\r\n%%\r\ntimes = {'7:17' '9:00'};\r\ny_correct = ['8:17' 3];\r\n[t_s,num] = equation_times_run(times);\r\nassert(isequal([t_s,num],y_correct))\r\n\r\n%%\r\ntimes = {'5:55' '9:00'};\r\ny_correct = ['6:15' 3];\r\n[t_s,num] = equation_times_run(times);\r\nassert(isequal([t_s,num],y_correct))\r\n\r\n%%\r\ntimes = {'1:00' '9:59'};\r\ny_correct = ['1:00' 24];\r\n[t_s,num] = equation_times_run(times);\r\nassert(isequal([t_s,num],y_correct))","published":true,"deleted":false,"likes_count":2,"comments_count":0,"created_by":26769,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":66,"test_suite_updated_at":null,"rescore_all_solutions":false,"group_id":45,"created_at":"2014-07-15T19:39:50.000Z","updated_at":"2026-01-15T14:27:21.000Z","published_at":"2014-07-15T19:39:50.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"relationships\":[{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/document\",\"targetMode\":\"\",\"relationshipId\":\"rId1\",\"target\":\"/matlab/document.xml\"},{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/output\",\"targetMode\":\"\",\"relationshipId\":\"rId2\",\"target\":\"/matlab/output.xml\"}],\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"relationship\":[],\"contentType\":\"application/vnd.mathworks.matlab.code.document+xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\\n\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eMany times throughout the day can represent mathematical equations. In this problem, we focus on the largest consecutive run of equation times that include one of the four basic operations (+,-,*,/) or the power operator (^). Find the largest such consecutive run for a given range of input times (based on three-digit 12-hour times, 1:00 to 9:59). Return the first time stamp (string) and the number of consecutive points (integer, inclusive) for the maximum run (the first run if there is a tie).\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eFor example, in the 2:07 to 2:29 time range, the answer is ['2:11' 3] since 2:10 has no equation, 2/1=1 (2:11), 2*1=2 (2:12), 2+1=3 (2:13) and 2:14 has no equation, and there are no such runs of four in that range.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eThis problem is related to\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:hyperlink w:docLocation=\\\"http://www.mathworks.com/matlabcentral/cody/problems/2431-power-times-of-the-day\\\"\u003e\u003cw:r\u003e\u003cw:t\u003eProblem 2431\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:hyperlink\u003e\u003cw:r\u003e\u003cw:t\u003e and\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:hyperlink w:docLocation=\\\"http://www.mathworks.com/matlabcentral/cody/problems/2432-equation-times-of-the-day\\\"\u003e\u003cw:r\u003e\u003cw:t\u003eProblem 2432\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:hyperlink\u003e\u003cw:r\u003e\u003cw:t\u003e.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\"},{\"partUri\":\"/matlab/output.xml\",\"contentType\":\"text/xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\" standalone=\\\"no\\\" ?\u003e\u003cembeddedOutputs\u003e\u003cmetaData\u003e\u003cevaluationState\u003emanual\u003c/evaluationState\u003e\u003clayoutState\u003ecode\u003c/layoutState\u003e\u003coutputStatus\u003eready\u003c/outputStatus\u003e\u003c/metaData\u003e\u003coutputArray type=\\\"array\\\"/\u003e\u003cregionArray 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