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Make a Palindrome Number

Some numbers like 323 are palindromes. Other numbers like 124 are not. But look what happens when we add that number to a revers...

8 months ago

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Which doors are open?

There are n doors in an alley. Initially they are all shut. You have been tasked to go down the alley n times, and open/shut the...

9 months 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...

9 months ago

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Making change

Given an amount of currency, return a vector of this form: [100 50 20 10 5 2 1 0.5 0.25 0.1 0.05 0.01] Example: Input a = ...

9 months 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...

9 months ago

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Make a checkerboard matrix

Given an integer n, make an n-by-n matrix made up of alternating ones and zeros as shown below. The a(1,1) should be 1. Examp...

9 months ago

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Who Has the Most Change?

You have a matrix for which each row is a person and the columns represent the number of quarters, nickels, dimes, and pennies t...

9 months ago

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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 ...

9 months ago

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Find the numeric mean of the prime numbers in a matrix.

There will always be at least one prime in the matrix. Example: Input in = [ 8 3 5 9 ] Output out is 4...

9 months 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...

9 months 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 ...

9 months ago

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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...

9 months 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 + ...

9 months 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...

9 months 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...

9 months ago

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Remove any row in which a NaN appears

Given the matrix A, return B in which all the rows that have one or more <http://www.mathworks.com/help/techdoc/ref/nan.html NaN...

9 months 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 ...

9 months 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...

9 months 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';

9 months ago

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De-dupe

Remove all the redundant elements in a vector, but keep the first occurrence of each value in its original location. So if a =...

9 months ago

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Clean the List of Names

Given a list of names in a cell array, remove any duplications that result from different capitalizations of the same string. So...

9 months ago

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Implement a ROT13 cipher

Replace each character in string s1 with the character that is shifted 13 positions from it (wrap back to the beginning if neces...

9 months ago

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DNA N-Gram Distribution

Given a string s and a number n, find the most frequently occurring n-gram in the string, where the n-grams can begin at any poi...

9 months 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 ...

9 months ago

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Remove the small words from a list of words.

Your job is to tidy up a list of words that appear in a string. The words are separated by one or more spaces. Remove all words ...

9 months ago

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Longest Divisor Run

Given the vector a, find the longest run of consecutive numbers that can be evenly divided by the same number d where d > 1. ...

9 months ago

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Renaming a field in a structure array

MATLAB has a <http://www.mathworks.com/help/techdoc/ref/setfield.html setfield> and a <http://www.mathworks.com/help/techdoc/ref...

9 months ago

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Indexed Probability Table

This question was inspired by a Stack Overflow question forwarded to me by Matt Simoneau. Given a vector x, make an indexed pro...

9 months ago

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It dseon't mettar waht oedrr the lrettes in a wrod are.

An internet meme from 2003 (read more <http://www.snopes.com/language/apocryph/cambridge.asp here>) asserted that readers are re...

9 months ago

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Counting in Finnish

Sort a vector of single digit whole numbers alphabetically by their name, in Finnish. See the Wikipedia page for <http://en.wik...

9 months ago