Solved

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

Solved

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

Solved

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

Solved

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

Solved

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

Solved

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

Solved

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

Solved

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

Solved

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

Solved

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

Solved

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

Solved

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

Solved

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

Answered
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

Solved

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

Solved

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

Solved

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

Solved

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

Solved

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

Solved

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

Answered
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

Solved

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

Solved

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

Solved

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

Solved

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

Solved

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

Solved

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

1 year ago

Solved

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

Solved

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