{"group":{"id":1,"name":"Community","lockable":false,"created_at":"2012-01-18T18:02:15.000Z","updated_at":"2026-06-05T00:10:21.000Z","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":"2026-06-05T00:00:00.000Z","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":51793,"title":"List the titles of Cody problems","description":"Cody has several ways to list problems, but I have not yet found an easy way to list them by their numbers. Listing by date created is close, but if someone starts a problem one day and finishes it much later, the numbers will be out of order. Even when the numbers are in order, finding a particular number can take some scrolling. One can type a URL with the problem number, but waiting for the page to load and being redirected to the main problems page gets cumbersome. \r\nWrite a function that takes a number or vector of numbers as input and returns a cell array of the titles of the problems. If the problem does not exist, return an empty vector in place of the title. ","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: 135px; display: block; min-width: 0px; padding-block-start: 0px; padding-top: 0px; perspective-origin: 408px 67.5px; transform-origin: 408px 67.5px; vertical-align: baseline; \"\u003e\u003cdiv style=\"block-size: 84px; 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: 385px 42px; text-align: left; transform-origin: 385px 42px; white-space-collapse: preserve; 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: 379.608px 8px; transform-origin: 379.608px 8px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003eCody has several ways to list problems, but I have not yet found an easy way to list them by their numbers. Listing by date created is close, but if someone starts a problem one day and finishes it much later, the numbers will be out of order. Even when the numbers are in order, finding a particular number can take some scrolling. One can type a URL with the problem number, but waiting for the page to load and being redirected to the main problems page gets cumbersome. \u003c/span\u003e\u003c/span\u003e\u003c/div\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: 385px 21px; text-align: left; transform-origin: 385px 21px; white-space-collapse: preserve; 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: 385px 8px; transform-origin: 385px 8px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003eWrite a function that takes a number or vector of numbers as input and returns a cell array of the titles of the problems. If the problem does not exist, return an empty vector in place of the title. \u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003c/div\u003e\u003c/div\u003e","function_template":"function y = CPtitle(n)\r\n  y = isCodyProblem(n);\r\nend","test_suite":"%%\r\nn = 60;\r\ny = CPtitle(n);\r\ny_correct = {'The Goldbach Conjecture'};\r\nassert(isequal(y,y_correct))\r\n\r\n%% \r\nn = 97;\r\ny = CPtitle(n);\r\nassert(isempty(y{1}))\r\n\r\n%%\r\nn = [1319 1515];\r\ny = CPtitle(n);\r\ny_correct = {'Leap years on other planets', 'Procrustean bed'};\r\nassert(isequal(y,y_correct))\r\n\r\n%%\r\nn = [45193 45196];\r\ny = CPtitle(n);\r\ny_correct = {'Fun with permutations', 'Determine whether a given point is inside or outside a polygon'};\r\nassert(isequal(y,y_correct))\r\n\r\n%%\r\nn = [45180 46898 47864];\r\ny = CPtitle(n);\r\ny_correct = {'All flights lead to Idaho Falls', 'Sum of all the divisors of n', 'Calculate the Surface Area of an Ellipsoid'};\r\nassert(isequal(y,y_correct))\r\n\r\n%%\r\nn = [44341 47673 47803];\r\ny = CPtitle(n);\r\ny_correct = {'Hexagonal numbers on a spiral matrix', 'Area under standard normal curve', 'Check if the input is a strong prime'};\r\nassert(isequal(y,y_correct))\r\n\r\n%%\r\nn = [42383 42415];\r\ny = CPtitle(n);\r\ny_correct = {['Combined Ages 3 - Non-symmetric, n ' char(8805) ' 3'], 'Divisible by 13'};\r\nassert(isequal(y,y_correct))\r\n\r\n%%\r\nn = [1215 2869];\r\ny = CPtitle(n);\r\ny_correct = {'Diophantine Equations (Inspired by Project Euler, problem 66)', 'There are 10 types of people in the world'};\r\nassert(isequal(y,y_correct))\r\n\r\n%%\r\nn = [44067 44068 44071];\r\ny = CPtitle(n);\r\ny_correct = {'The last non-zero digit of a factorial', 'The number of trailing zero digit of a factorial', 'Smallest n, for n! to have m trailing zero digits'};\r\nassert(isequal(y,y_correct))\r\n\r\n%%\r\nn = [45272 45302 45339];\r\ny = CPtitle(n);\r\ny_correct = {'Pseudo-vampire number ', 'Ugly numbers - 03', 'XOR fibonacci'};\r\nassert(isequal(y,y_correct))\r\n\r\n%%\r\nn = 46072;\r\ny = CPtitle(n);\r\ny_correct = {'Rock Paper Scissors Lizard Spock'};\r\nassert(isequal(y,y_correct))\r\n\r\n%%\r\nn = [51630 51640];\r\ny = CPtitle(n);\r\ny_correct = {'Highest building', 'Similar triangles'};\r\nassert(isequal(y,y_correct))\r\n\r\n%%\r\nn = 1012:1015;\r\ny = CPtitle(n);\r\ny_correct = {'Determine if input is a perfect number', [], [], 'Polynomial Interpolation'};\r\nassert(isequal(y,y_correct))\r\n\r\n%%\r\nn = 42240:42250;\r\ny = CPtitle(n(randi(11,1,2)));\r\nassert(all(arrayfun(@(k) isempty(y{k}),1:2)))\r\n\r\n%%\r\nn = 8047+randi(8);\r\ny1 = CPtitle(n);\r\ns = y1{1};\r\nc = split(CPtitle(sum(double(s(1:13)))));\r\nassert(isequal(c{4},'Awesome'))\r\n","published":true,"deleted":false,"likes_count":3,"comments_count":1,"created_by":46909,"edited_by":46909,"edited_at":"2025-07-16T16:53:28.000Z","deleted_by":null,"deleted_at":null,"solvers_count":8,"test_suite_updated_at":null,"rescore_all_solutions":false,"group_id":1,"created_at":"2021-05-18T05:40:12.000Z","updated_at":"2026-05-31T13:24:33.000Z","published_at":"2021-05-18T05:44:30.000Z","restored_at":null,"restored_by":null,"spam":null,"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\u003eCody has several ways to list problems, but I have not yet found an easy way to list them by their numbers. Listing by date created is close, but if someone starts a problem one day and finishes it much later, the numbers will be out of order. Even when the numbers are in order, finding a particular number can take some scrolling. One can type a URL with the problem number, but waiting for the page to load and being redirected to the main problems page gets cumbersome. \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\u003eWrite a function that takes a number or vector of numbers as input and returns a cell array of the titles of the problems. If the problem does not exist, return an empty vector in place of the title. \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":781,"title":"Access a web hosted copy of the Tiles Contest MAT file","description":"Access a web hosted copy of the Tiles Contest sample \"mat\" and verify success by returning for a board the number of tiles, number of rows, and number of columns of the board.\r\n\r\nDetails of the Tiles Contest can be found at \u003chttp://www.mathworks.com/matlabcentral/contest/contests/36 Tiles Contest\u003e.\r\n\r\nThe runcontest.m provides testsuite structure information.\r\n\r\n*Input:* (urlfname, board)\r\n\r\nfn='http://www.toobigforemail.com/cryptkeeper.toobig?nppmkc2=xyeffg\u00266cq_kc2=yae1d8\u00266cq_konmpb=y88ayxyx8xxy1xdyx'\r\n\r\n*Output:* (number of tiles, nrows, ncols)\r\n\r\nFor board 99\r\n\r\n[ 20 10 8 ]\r\n\r\n\r\n\r\nNote: The mat file is a very efficiently packed binary file.\r\n\r\nFollow-up questions will be creation of a mat file and a timed contest for a few of the perfectly solveable Tile boards","description_html":"\u003cp\u003eAccess a web hosted copy of the Tiles Contest sample \"mat\" and verify success by returning for a board the number of tiles, number of rows, and number of columns of the board.\u003c/p\u003e\u003cp\u003eDetails of the Tiles Contest can be found at \u003ca href=\"http://www.mathworks.com/matlabcentral/contest/contests/36\"\u003eTiles Contest\u003c/a\u003e.\u003c/p\u003e\u003cp\u003eThe runcontest.m provides testsuite structure information.\u003c/p\u003e\u003cp\u003e\u003cb\u003eInput:\u003c/b\u003e (urlfname, board)\u003c/p\u003e\u003cp\u003efn='http://www.toobigforemail.com/cryptkeeper.toobig?nppmkc2=xyeffg\u00266cq_kc2=yae1d8\u00266cq_konmpb=y88ayxyx8xxy1xdyx'\u003c/p\u003e\u003cp\u003e\u003cb\u003eOutput:\u003c/b\u003e (number of tiles, nrows, ncols)\u003c/p\u003e\u003cp\u003eFor board 99\u003c/p\u003e\u003cp\u003e[ 20 10 8 ]\u003c/p\u003e\u003cp\u003eNote: The mat file is a very efficiently packed binary file.\u003c/p\u003e\u003cp\u003eFollow-up questions will be creation of a mat file and a timed contest for a few of the perfectly solveable Tile boards\u003c/p\u003e","function_template":"function out = access_url_mat(urlfname,brd)\r\n \r\n %tiles=tests.testsuite(brd).tiles;\r\n\r\n ntiles=1;nrow=1;ncol=1;\r\n \r\n out=[ntiles nrow ncol];\r\n\r\nend","test_suite":"%%\r\n% Cody External accessibility\r\ny=clock;\r\nrand('state',floor(10000*y(6)))\r\nbrd=randi(100,1)\r\n\r\nfn='http://www.toobigforemail.com/cryptkeeper.toobig?nppmkc2=xyeffg\u00266cq_kc2=yae1d8\u00266cq_konmpb=y88ayxyx8xxy1xdyx';\r\n\r\nfn='http://tinyurl.com/matlab-tiles-mat';\r\ntestSuiteFile = 'raz_tiles.mat';\r\nurlwrite(fn,testSuiteFile);\r\n\r\ntests = load(testSuiteFile,'testsuite');\r\n\r\ntiles = tests.testsuite(brd).tiles;\r\nrows = tests.testsuite(brd).r;\r\ncols = tests.testsuite(brd).c;\r\n\r\nexpected=[size(tiles,1) rows cols]\r\n\r\nout=access_url_mat(fn,brd)\r\n\r\nassert(isequal(out,expected))\r\n%%\r\nbrd=randi(100,1)\r\n\r\nfn='http://www.toobigforemail.com/cryptkeeper.toobig?nppmkc2=xyeffg\u00266cq_kc2=yae1d8\u00266cq_konmpb=y88ayxyx8xxy1xdyx';\r\n\r\nfn='http://tinyurl.com/matlab-tiles-mat';\r\ntestSuiteFile = 'raz_tiles.mat';\r\nurlwrite(fn,testSuiteFile);\r\n\r\ntests = load(testSuiteFile,'testsuite');\r\n\r\ntiles = tests.testsuite(brd).tiles;\r\nrows = tests.testsuite(brd).r;\r\ncols = tests.testsuite(brd).c;\r\n\r\nexpected=[size(tiles,1) rows cols]\r\n\r\nout=access_url_mat(fn,brd)\r\n\r\nassert(isequal(out,expected))\r\n","published":true,"deleted":false,"likes_count":0,"comments_count":2,"created_by":3097,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":8,"test_suite_updated_at":"2012-11-22T12:22:58.000Z","rescore_all_solutions":false,"group_id":1,"created_at":"2012-06-21T04:54:17.000Z","updated_at":"2026-05-26T16:59:49.000Z","published_at":"2012-06-22T04:40:01.000Z","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\u003eAccess a web hosted copy of the Tiles Contest sample \\\"mat\\\" and verify success by returning for a board the number of tiles, number of rows, and number of columns of the board.\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\u003eDetails of the Tiles Contest can be found at\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/contest/contests/36\\\"\u003e\u003cw:r\u003e\u003cw:t\u003eTiles Contest\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 runcontest.m provides testsuite structure information.\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 (urlfname, board)\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\u003efn='http://www.toobigforemail.com/cryptkeeper.toobig?nppmkc2=xyeffg\u0026amp;6cq_kc2=yae1d8\u0026amp;6cq_konmpb=y88ayxyx8xxy1xdyx'\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 (number of tiles, nrows, ncols)\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 board 99\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\u003e[ 20 10 8 ]\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: The mat file is a very efficiently packed binary file.\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\u003eFollow-up questions will be creation of a mat file and a timed contest for a few of the perfectly solveable Tile boards\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":{"problems":[{"id":51793,"title":"List the titles of Cody problems","description":"Cody has several ways to list problems, but I have not yet found an easy way to list them by their numbers. Listing by date created is close, but if someone starts a problem one day and finishes it much later, the numbers will be out of order. Even when the numbers are in order, finding a particular number can take some scrolling. One can type a URL with the problem number, but waiting for the page to load and being redirected to the main problems page gets cumbersome. \r\nWrite a function that takes a number or vector of numbers as input and returns a cell array of the titles of the problems. If the problem does not exist, return an empty vector in place of the title. ","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: 135px; display: block; min-width: 0px; padding-block-start: 0px; padding-top: 0px; perspective-origin: 408px 67.5px; transform-origin: 408px 67.5px; vertical-align: baseline; \"\u003e\u003cdiv style=\"block-size: 84px; 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: 385px 42px; text-align: left; transform-origin: 385px 42px; white-space-collapse: preserve; 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: 379.608px 8px; transform-origin: 379.608px 8px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003eCody has several ways to list problems, but I have not yet found an easy way to list them by their numbers. Listing by date created is close, but if someone starts a problem one day and finishes it much later, the numbers will be out of order. Even when the numbers are in order, finding a particular number can take some scrolling. One can type a URL with the problem number, but waiting for the page to load and being redirected to the main problems page gets cumbersome. \u003c/span\u003e\u003c/span\u003e\u003c/div\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: 385px 21px; text-align: left; transform-origin: 385px 21px; white-space-collapse: preserve; 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: 385px 8px; transform-origin: 385px 8px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003eWrite a function that takes a number or vector of numbers as input and returns a cell array of the titles of the problems. If the problem does not exist, return an empty vector in place of the title. \u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003c/div\u003e\u003c/div\u003e","function_template":"function y = CPtitle(n)\r\n  y = isCodyProblem(n);\r\nend","test_suite":"%%\r\nn = 60;\r\ny = CPtitle(n);\r\ny_correct = {'The Goldbach Conjecture'};\r\nassert(isequal(y,y_correct))\r\n\r\n%% \r\nn = 97;\r\ny = CPtitle(n);\r\nassert(isempty(y{1}))\r\n\r\n%%\r\nn = [1319 1515];\r\ny = CPtitle(n);\r\ny_correct = {'Leap years on other planets', 'Procrustean bed'};\r\nassert(isequal(y,y_correct))\r\n\r\n%%\r\nn = [45193 45196];\r\ny = CPtitle(n);\r\ny_correct = {'Fun with permutations', 'Determine whether a given point is inside or outside a polygon'};\r\nassert(isequal(y,y_correct))\r\n\r\n%%\r\nn = [45180 46898 47864];\r\ny = CPtitle(n);\r\ny_correct = {'All flights lead to Idaho Falls', 'Sum of all the divisors of n', 'Calculate the Surface Area of an Ellipsoid'};\r\nassert(isequal(y,y_correct))\r\n\r\n%%\r\nn = [44341 47673 47803];\r\ny = CPtitle(n);\r\ny_correct = {'Hexagonal numbers on a spiral matrix', 'Area under standard normal curve', 'Check if the input is a strong prime'};\r\nassert(isequal(y,y_correct))\r\n\r\n%%\r\nn = [42383 42415];\r\ny = CPtitle(n);\r\ny_correct = {['Combined Ages 3 - Non-symmetric, n ' char(8805) ' 3'], 'Divisible by 13'};\r\nassert(isequal(y,y_correct))\r\n\r\n%%\r\nn = [1215 2869];\r\ny = CPtitle(n);\r\ny_correct = {'Diophantine Equations (Inspired by Project Euler, problem 66)', 'There are 10 types of people in the world'};\r\nassert(isequal(y,y_correct))\r\n\r\n%%\r\nn = [44067 44068 44071];\r\ny = CPtitle(n);\r\ny_correct = {'The last non-zero digit of a factorial', 'The number of trailing zero digit of a factorial', 'Smallest n, for n! to have m trailing zero digits'};\r\nassert(isequal(y,y_correct))\r\n\r\n%%\r\nn = [45272 45302 45339];\r\ny = CPtitle(n);\r\ny_correct = {'Pseudo-vampire number ', 'Ugly numbers - 03', 'XOR fibonacci'};\r\nassert(isequal(y,y_correct))\r\n\r\n%%\r\nn = 46072;\r\ny = CPtitle(n);\r\ny_correct = {'Rock Paper Scissors Lizard Spock'};\r\nassert(isequal(y,y_correct))\r\n\r\n%%\r\nn = [51630 51640];\r\ny = CPtitle(n);\r\ny_correct = {'Highest building', 'Similar triangles'};\r\nassert(isequal(y,y_correct))\r\n\r\n%%\r\nn = 1012:1015;\r\ny = CPtitle(n);\r\ny_correct = {'Determine if input is a perfect number', [], [], 'Polynomial Interpolation'};\r\nassert(isequal(y,y_correct))\r\n\r\n%%\r\nn = 42240:42250;\r\ny = CPtitle(n(randi(11,1,2)));\r\nassert(all(arrayfun(@(k) isempty(y{k}),1:2)))\r\n\r\n%%\r\nn = 8047+randi(8);\r\ny1 = CPtitle(n);\r\ns = y1{1};\r\nc = split(CPtitle(sum(double(s(1:13)))));\r\nassert(isequal(c{4},'Awesome'))\r\n","published":true,"deleted":false,"likes_count":3,"comments_count":1,"created_by":46909,"edited_by":46909,"edited_at":"2025-07-16T16:53:28.000Z","deleted_by":null,"deleted_at":null,"solvers_count":8,"test_suite_updated_at":null,"rescore_all_solutions":false,"group_id":1,"created_at":"2021-05-18T05:40:12.000Z","updated_at":"2026-05-31T13:24:33.000Z","published_at":"2021-05-18T05:44:30.000Z","restored_at":null,"restored_by":null,"spam":null,"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\u003eCody has several ways to list problems, but I have not yet found an easy way to list them by their numbers. Listing by date created is close, but if someone starts a problem one day and finishes it much later, the numbers will be out of order. Even when the numbers are in order, finding a particular number can take some scrolling. One can type a URL with the problem number, but waiting for the page to load and being redirected to the main problems page gets cumbersome. \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\u003eWrite a function that takes a number or vector of numbers as input and returns a cell array of the titles of the problems. If the problem does not exist, return an empty vector in place of the title. \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":781,"title":"Access a web hosted copy of the Tiles Contest MAT file","description":"Access a web hosted copy of the Tiles Contest sample \"mat\" and verify success by returning for a board the number of tiles, number of rows, and number of columns of the board.\r\n\r\nDetails of the Tiles Contest can be found at \u003chttp://www.mathworks.com/matlabcentral/contest/contests/36 Tiles Contest\u003e.\r\n\r\nThe runcontest.m provides testsuite structure information.\r\n\r\n*Input:* (urlfname, board)\r\n\r\nfn='http://www.toobigforemail.com/cryptkeeper.toobig?nppmkc2=xyeffg\u00266cq_kc2=yae1d8\u00266cq_konmpb=y88ayxyx8xxy1xdyx'\r\n\r\n*Output:* (number of tiles, nrows, ncols)\r\n\r\nFor board 99\r\n\r\n[ 20 10 8 ]\r\n\r\n\r\n\r\nNote: The mat file is a very efficiently packed binary file.\r\n\r\nFollow-up questions will be creation of a mat file and a timed contest for a few of the perfectly solveable Tile boards","description_html":"\u003cp\u003eAccess a web hosted copy of the Tiles Contest sample \"mat\" and verify success by returning for a board the number of tiles, number of rows, and number of columns of the board.\u003c/p\u003e\u003cp\u003eDetails of the Tiles Contest can be found at \u003ca href=\"http://www.mathworks.com/matlabcentral/contest/contests/36\"\u003eTiles Contest\u003c/a\u003e.\u003c/p\u003e\u003cp\u003eThe runcontest.m provides testsuite structure information.\u003c/p\u003e\u003cp\u003e\u003cb\u003eInput:\u003c/b\u003e (urlfname, board)\u003c/p\u003e\u003cp\u003efn='http://www.toobigforemail.com/cryptkeeper.toobig?nppmkc2=xyeffg\u00266cq_kc2=yae1d8\u00266cq_konmpb=y88ayxyx8xxy1xdyx'\u003c/p\u003e\u003cp\u003e\u003cb\u003eOutput:\u003c/b\u003e (number of tiles, nrows, ncols)\u003c/p\u003e\u003cp\u003eFor board 99\u003c/p\u003e\u003cp\u003e[ 20 10 8 ]\u003c/p\u003e\u003cp\u003eNote: The mat file is a very efficiently packed binary file.\u003c/p\u003e\u003cp\u003eFollow-up questions will be creation of a mat file and a timed contest for a few of the perfectly solveable Tile boards\u003c/p\u003e","function_template":"function out = access_url_mat(urlfname,brd)\r\n \r\n %tiles=tests.testsuite(brd).tiles;\r\n\r\n ntiles=1;nrow=1;ncol=1;\r\n \r\n out=[ntiles nrow ncol];\r\n\r\nend","test_suite":"%%\r\n% Cody External accessibility\r\ny=clock;\r\nrand('state',floor(10000*y(6)))\r\nbrd=randi(100,1)\r\n\r\nfn='http://www.toobigforemail.com/cryptkeeper.toobig?nppmkc2=xyeffg\u00266cq_kc2=yae1d8\u00266cq_konmpb=y88ayxyx8xxy1xdyx';\r\n\r\nfn='http://tinyurl.com/matlab-tiles-mat';\r\ntestSuiteFile = 'raz_tiles.mat';\r\nurlwrite(fn,testSuiteFile);\r\n\r\ntests = load(testSuiteFile,'testsuite');\r\n\r\ntiles = tests.testsuite(brd).tiles;\r\nrows = tests.testsuite(brd).r;\r\ncols = tests.testsuite(brd).c;\r\n\r\nexpected=[size(tiles,1) rows cols]\r\n\r\nout=access_url_mat(fn,brd)\r\n\r\nassert(isequal(out,expected))\r\n%%\r\nbrd=randi(100,1)\r\n\r\nfn='http://www.toobigforemail.com/cryptkeeper.toobig?nppmkc2=xyeffg\u00266cq_kc2=yae1d8\u00266cq_konmpb=y88ayxyx8xxy1xdyx';\r\n\r\nfn='http://tinyurl.com/matlab-tiles-mat';\r\ntestSuiteFile = 'raz_tiles.mat';\r\nurlwrite(fn,testSuiteFile);\r\n\r\ntests = load(testSuiteFile,'testsuite');\r\n\r\ntiles = tests.testsuite(brd).tiles;\r\nrows = tests.testsuite(brd).r;\r\ncols = tests.testsuite(brd).c;\r\n\r\nexpected=[size(tiles,1) rows cols]\r\n\r\nout=access_url_mat(fn,brd)\r\n\r\nassert(isequal(out,expected))\r\n","published":true,"deleted":false,"likes_count":0,"comments_count":2,"created_by":3097,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":8,"test_suite_updated_at":"2012-11-22T12:22:58.000Z","rescore_all_solutions":false,"group_id":1,"created_at":"2012-06-21T04:54:17.000Z","updated_at":"2026-05-26T16:59:49.000Z","published_at":"2012-06-22T04:40:01.000Z","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\u003eAccess a web hosted copy of the Tiles Contest sample \\\"mat\\\" and verify success by returning for a board the number of tiles, number of rows, and number of columns of the board.\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\u003eDetails of the Tiles Contest can be found at\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/contest/contests/36\\\"\u003e\u003cw:r\u003e\u003cw:t\u003eTiles Contest\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 runcontest.m provides testsuite structure information.\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 (urlfname, board)\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\u003efn='http://www.toobigforemail.com/cryptkeeper.toobig?nppmkc2=xyeffg\u0026amp;6cq_kc2=yae1d8\u0026amp;6cq_konmpb=y88ayxyx8xxy1xdyx'\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 (number of tiles, nrows, ncols)\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 board 99\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\u003e[ 20 10 8 ]\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: The mat file is a very efficiently packed binary file.\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\u003eFollow-up questions will be creation of a mat file and a timed contest for a few of the perfectly solveable Tile boards\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\"}]}"}],"errors":[],"facets":[[],[{"value":"medium","count":2,"selected":false}]],"term":"tag:\"url\"","page":1,"per_page":50,"sort":"map(difficulty_value,0,0,999) asc"}}