uhh

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Kaprekar Steps

6174 is the <http://en.wikipedia.org/wiki/6174_%28number%29 Kaprekar constant>. All natural numbers less than 10,000 (except som...

2 years ago

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Find the peak 3n+1 sequence value

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...

2 years ago

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Alphabetize by last name

Given a list of names in a cell array, sort the list by the last name. So if list = {'Barney Google','Snuffy Smith','Dagwood ...

2 years ago

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Read a column of numbers and interpolate missing data

Given an input cell array of strings s, pick out the second column and turn it into a row vector of data. Missing data will be i...

2 years ago

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How long is the longest prime diagonal?

Stanislaw Ulam once observed that if the counting numbers are <http://en.wikipedia.org/wiki/Ulam_spiral arranged in a spiral>, t...

3 years ago

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Find the biggest empty box

You are given a matrix that contains only ones and zeros. Think of the ones as columns in an otherwise empty floor plan. You wan...

3 years ago

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Spot the outlier

All points except for one lie on a line. Which one is the outlier? Example: You are given a list of x-y pairs in a column ...

3 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...

3 years ago

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How many trades represent all the profit?

Given a list of results from trades made: [1 3 -4 2 -1 2 3] We can add them up to see this series of trades made a profit ...

3 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 ...

3 years ago

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Flag largest magnitude swings as they occur

You have a phenomenon that produces strictly positive or negative results. delta = [1 -3 4 2 -1 6 -2 -7]; Marching thr...

3 years ago

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Make a run-length companion vector

Given a vector x, return a vector r that indicates the run length of any value in x. Each element in r shows how many times the ...

3 years ago

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Find a subset that divides the vector into equal halves

Given a vector x, return the indices to elements that will sum to exactly half of the sum of all elements. Example: Inpu...

3 years ago

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Add two numbers

Calculate the sum of two numbers. Example input = [2 3] output = 5

3 years ago

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Back to basics 6 - Column Vector

Covering some basic topics I haven't seen elsewhere on Cody. Given an input vector, output true or false whether it is a colu...

3 years ago

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Solve the Sudoku Row

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

3 years ago

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Get the length of a given vector

Given a vector x, the output y should equal the length of x.

3 years ago

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Find the largest value in the 3D matrix

Given a 3D matrix A, find the largest value. Example >> A = 1:9; >> A = reshape(A,[3 1 3]); >> islargest(A) a...

3 years ago

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Side of a rhombus

If a rhombus has diagonals of length x and x+1, then what is the length of its side, y? <<http://upload.wikimedia.org/wikipe...

3 years ago

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Extract leading non-zero digit

<http://en.wikipedia.org/wiki/Benford%27s_law Benford's Law> states that the distribution of leading digits is not random. This...

3 years ago

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Right and wrong

Given a vector of lengths [a b c], determines whether a triangle with those sides lengths is a right triangle: <http://en.wikipe...

3 years ago

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Sums with Excluded Digits

Add all the integers from 1 to n in which the digit m does not appear. m will always be a single digit integer from 0 to 9. no...

3 years ago

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Back to basics 21 - Matrix replicating

Covering some basic topics I haven't seen elsewhere on Cody. Given an input matrix, generate an output matrix that consists o...

3 years ago

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Find the sum of the elements in the "second" diagonal

Find the sum of the elements in the diagonal that starts at the top-right corner and ends at the bottom-left corner.

3 years ago

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QWERTY coordinates

Given a lowercase letter or a digit as input, return the row where that letter appears on a <http://en.wikipedia.org/wiki/Keyboa...

3 years ago

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Return the first and last character of a string

Return the first and last character of a string, concatenated together. If there is only one character in the string, the functi...

3 years ago

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Remove all the words that end with "ain"

Given the string s1, return the string s2 with the target characters removed. For example, given s1 = 'the main event' your ...

3 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...

3 years ago

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Find a Pythagorean triple

Given four different positive numbers, a, b, c and d, provided in increasing order: a < b < c < d, find if any three of them com...

3 years ago

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Dimensions of a rectangle

The longer side of a rectangle is three times the length of the shorter side. If the length of the diagonal is x, find the width...

3 years ago