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Remove the polynomials that have positive real elements of their roots.
The characteristic equation for a dynamic system is a polynomial whose roots indicate its behavior. If any of the roots of the p...

1 year ago

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Mandelbrot Numbers
The <http://en.wikipedia.org/wiki/Mandelbrot_set Mandelbrot Set> is built around a simple iterative equation. z(1) = c z...

1 year ago

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Find common elements in matrix rows
Given a matrix, find all elements that exist in every row. For example, given A = 1 2 3 5 9 2 5 9 3 2 5 9 ...

1 year ago

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Given two arrays, find the maximum overlap
Given two (integer) arrays s1 and s2, create a new array s3 which is as short as possible and contains both arrays. #1 s1 = [...

1 year ago

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Kaprekar Steps
6174 is the Kaprekar constant. All natural numbers less than 10,000 (except some with same digits) can be reduced to 6174 in the...

1 year ago

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Swap the first and last columns
Flip the outermost columns of matrix A, so that the first column becomes the last and the last column becomes the first. All oth...

1 year ago

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Return a list sorted by number of occurrences
Given a vector x, return a vector y of the unique values in x sorted by the number of occurrences in x. Ties are resolved by a ...

1 year ago

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It dseon't mettar waht oedrr the lrettes in a wrod are.
An internet meme from 2003 (read more here) asserted that readers are relatively insensitive to letter order in words, so long a...

1 year ago

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Calculate the Levenshtein distance between two strings
This problem description is lifted from http://en.wikipedia.org/wiki/Levenshtein_distance. The Levenshtein distance between two...

1 year ago

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Determine whether a vector is monotonically increasing
Return true if the elements of the input vector increase monotonically (i.e. each element is larger than the previous). Return f...

1 year ago

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Find the palindrome
Given the string a, find the longest palindromic sub-string b. So when a = 'xkayakyy'; you should return b = 'kayak';

1 year ago

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Counting Sequence
Given a vector x, find the "counting sequence" y. A counting sequence is formed by "counting" the entries in a given sequence...

1 year ago

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Subset Sum
Given a vector v of integers and an integer n, return the the indices of v (as a row vector in ascending order) that sum to n. I...

1 year ago

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Cody Problem 38. Return a list sorted by number of occurrences
function output_array = popularity(input_array) %% First make unique array unique_input_array = unique(input_array); %% C...

1 year ago | 0

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Binary numbers
Given a positive, scalar integer n, create a (2^n)-by-n double-precision matrix containing the binary numbers from 0 through 2^n...

1 year ago

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Which values occur exactly three times?
Return a list of all values (sorted smallest to largest) that appear exactly three times in the input vector x. So if x = [1 2...

1 year ago

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Most nonzero elements in row
Given the matrix a, return the index r of the row with the most nonzero elements. Assume there will always be exactly one row th...

1 year ago

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Remove the vowels
Remove all the vowels in the given phrase. Example: Input s1 = 'Jack and Jill went up the hill' Output s2 is 'Jck nd Jll wn...

1 year ago

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Return the 3n+1 sequence for n
A Collatz sequence is the sequence where, for a given number n, the next number in the sequence is either n/2 if the number is e...

1 year ago

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Summing digits
Given n, find the sum of the digits that make up 2^n. Example: Input n = 7 Output b = 11 since 2^7 = 128, and 1 + ...

1 year ago

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Cody Problem 19. Swap the first and last columns
function B = swap_ends(A) B = A; k = B(:,1); B(:,1) = B(:,end); B(:,end) = k; end

1 year ago | 0

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Bullseye Matrix
Given n (always odd), return output a that has concentric rings of the numbers 1 through (n+1)/2 around the center point. Exampl...

1 year ago

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Find all elements less than 0 or greater than 10 and replace them with NaN
Given an input vector x, find all elements of x less than 0 or greater than 10 and replace them with NaN. Example: Input ...

1 year ago

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Return the largest number that is adjacent to a zero
This example comes from Steve Eddins' blog: <http://blogs.mathworks.com/steve/2009/05/27/learning-lessons-from-a-one-liner/ Lear...

1 year ago

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Find the longest sequence of 1's in a binary sequence.
Given a string such as s = '011110010000000100010111' find the length of the longest string of consecutive 1's. In this examp...

1 year ago

Answered
Cody Problem 14. Find the numeric mean of the prime numbers in a matrix.
function out = meanOfPrimes(in) primeTF = isprime(in); primeTFIndex = find(primeTF); x = []; for...

1 year ago | 0

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Remove all the consonants
Remove all the consonants in the given phrase. Example: Input s1 = 'Jack and Jill went up the hill'; Output s2 is 'a ...

1 year ago

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Add two numbers
Given a and b, return the sum a+b in c.

1 year ago

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Select every other element of a vector
Write a function which returns every other element of the vector passed in. That is, it returns the all odd-numbered elements, s...

1 year ago

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Triangle Numbers
Triangle numbers are the sums of successive integers. So 6 is a triangle number because 6 = 1 + 2 + 3 which can be displayed ...

1 year ago

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