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So many choices
For inputs _n_ and _k_ (in that order), output the number of ways that k objects can be chosen from amongst n distinct objects. ...

8 years ago

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Back to basics 22 - Rotate a matrix
Covering some basic topics I haven't seen elsewhere on Cody. Rotate the input matrix 90 degrees counterclockwise (e.g. [1 2; ...

8 years ago

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Test for balanced parentheses
Given the input inStr, give the boolean output out indicating whether all the parentheses are balanced. Examples: * If ...

8 years ago

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Is the Point in a Circle?
Check whether a point or multiple points is/are in a circle centered at point (x0, y0) with radius r. Points = [x, y]; c...

8 years ago

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Insert zeros into vector
Insert zeros after each elements in the vector. Number of zeros is specified as the input parameter. For example: x = [1 ...

8 years ago

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Zero Cross
Write a function that counts the number of times n a signal x changes sign. Examples x = [1 2 -3 -4 5 6 -7 8 -9 10 11] ...

8 years ago

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intersection of matrices
Given two matrices filled with ones and zeros, determine if they share a common row, column entry. These matrices are of identi...

8 years ago

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Get the elements of diagonal and antidiagonal for any m-by-n matrix
In the problem <http://www.mathworks.com/matlabcentral/cody/problems/858-permute-diagonal-and-antidiagonal Problem 858. Permute ...

8 years ago

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Getting the indices from a matrice
Getting the indices from a matrice. Inspired by Problem 645. Getting the indices from a vector by the great Doug Hull. Given a...

8 years ago

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Construct an index vector from two input vectors in vectorized fashion
Create an index vector defined by two input vectors, one defining the beginnings of one or more index ranges, and the other defi...

8 years ago

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"Low : High - Low : High - Turn around " -- Create a subindices vector
Let two vectors *lo* and *hi* be given. The job is to create a index vector like so idx = [lo(1):hi(1) lo(2):hi(2) ...]...

8 years ago

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Implement simple rotation cypher
If given a letter from the set: [abc...xyz] and a shift, implement a shift cypher. Example: 'abc' with a shi...

8 years ago

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Pernicious Anniversary Problem
Since Cody is 5 years old, it's pernicious. A <http://rosettacode.org/wiki/Pernicious_numbers Pernicious number> is an integer w...

8 years ago

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middleAsColumn: Return all but first and last element as a column vector
Given input A, return all but the first and last elements, arranged as a column vector. (I.e., all dimensions after the first s...

8 years ago

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Fill a zeros matrix
The aim is to fill an array of all zeros given a numerical value and the index of row and columns for this value. 3 Inputs: ...

8 years ago

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We love vectorized solutions. Problem 1 : remove the row average.
Given a 2-d matrix, remove the row average from each row. Your solution MUST be vectorized. The solution will be tested for ac...

8 years ago

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Number of 1s in a binary string
Find the number of 1s in the given binary string. Example. If the input string is '1100101', the output is 4. If the input stri...

8 years ago

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Project Euler: Problem 1, Multiples of 3 and 5
If we list all the natural numbers below 10 that are multiples of 3 or 5, we get 3, 5, 6 and 9. The sum of these multiples is 23...

8 years ago

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Balanced number
Given a positive integer find whether it is a balanced number. For a balanced number the sum of first half of digits is equal to...

8 years ago

Solved

Create a vector whose elements depend on the previous element
The idea is to create a vector A whose elements depend on the previous element : *A(i+1) = 2*A(i)+1* *2 Inputs*: - A : The...

8 years ago

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Getting the indices from a vector
This is a basic MATLAB operation. It is for instructional purposes. --- You may already know how to <http://www.mathworks....

8 years ago

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Generate a vector like 1,2,2,3,3,3,4,4,4,4
Generate a vector like 1,2,2,3,3,3,4,4,4,4 So if n = 3, then return [1 2 2 3 3 3] And if n = 5, then return [1 2 2...

8 years ago

Solved

Solve the Sudoku Row
*Description* A simple yet tedious task occurs near the end of most Sudoku-solving algorithms, computerized or manual. The ta...

8 years ago

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Replace NaNs with the number that appears to its left in the row.
Replace NaNs with the number that appears to its left in the row. If there are more than one consecutive NaNs, they should all ...

8 years ago

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Alternating sum
Given vector x, calculate the alternating sum y = x(1) - x(2) + x(3) - x(4) + ...

8 years ago

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Kaprekar numbers
Test if the input is a Kaprekar number: <http://mathworld.wolfram.com/KaprekarNumber.html>. Return a logical true or false. ...

8 years ago

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Parasitic numbers
Test whether the first input x is an n-parasitic number: <http://en.wikipedia.org/wiki/Parasitic_number>. ( _n_ is the second in...

8 years ago

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Compute Fibonacci Number
Compute the _n_-th Fibonacci Number f(0) = 0, f(1) = 1, f(2) = 1, f(3) = 2, ... f(42) = 267914296

8 years ago

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Determine if a Given Number is a Triangle Number
*Description:* Determine if the elements of an input array are triangle numbers and return the result as an array with the sa...

8 years ago

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Given a window, how many subsets of a vector sum positive
Given a vector: [1 0 -1 3 2 -3 1] and a window of 2, A sliding window would find: 1 + 0 = 1 0 - 1 = -1 ...

8 years ago