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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...

4 years ago

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Is my wife right? Now with even more wrong husband
Again, as in "Is my wife right?" ( <http://www.mathworks.com/matlabcentral/cody/problems/149-is-my-wife-right> ), answer 'yes' r...

4 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 ...

4 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...

4 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...

4 years ago

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Tell me the slope
Tell me the slope, given a vector with horizontal run first and vertical rise next. Example input: x = [10 2];

4 years ago

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Duplicates
Write a function that accepts a cell array of strings and returns another cell array of strings *with only the duplicates* retai...

4 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...

4 years ago

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Matlab Basics - Rounding III
Write a script to round a large number to the nearest 10,000 e.g. x = 12,358,466,243 --> y = 12,358,470,000

4 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...

4 years ago

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Sorted highest to lowest?
Return 1 if the input is sorted from highest to lowest, 0 if not. Example: 1:7 -> 0 [7 5 2] -> 1

4 years ago

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Sum of diagonal of a square matrix
If x = [1 2 4; 3 4 5; 5 6 7] then y should be the sum of the diagonals of the matrix y = 1 + 4 + 7 = 12

4 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 ...

4 years ago

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Rounding off numbers to n decimals
Inspired by a mistake in one of the problems I created, I created this problem where you have to round off a floating point numb...

4 years ago

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The Goldbach Conjecture, Part 2
The <http://en.wikipedia.org/wiki/Goldbach's_conjecture Goldbach conjecture> asserts that every even integer greater than 2 can ...

4 years ago

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Check that number is whole number
Check that number is whole number Say x=15, then answer is 1. x=15.2 , then answer is 0. <http://en.wikipedia.org/wiki/Whole...

4 years ago

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How to subtract?
*&plusmn &plusmn &plusmn &plusmn &plusmn &plusmn &plusmn &plusmn &plusmn &plusmn &plusmn* * Imagine you need to subtract one...

4 years 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 ...

4 years ago

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Matlab Basics - Rounding II
Write a script to round a variable x to 3 decimal places: e.g. x = 2.3456 --> y = 2.346

4 years ago

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Summing Digits within Text
Given a string with text and digits, add all the numbers together. Examples: Input str = '4 and 20 blackbirds baked in a...

4 years 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...

4 years ago

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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...

4 years ago

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MATLAB Basic: rounding III
Do rounding towards minus infinity. Example: -8.8, answer -9 +8.1 answer 8 +8.50 answer 8

4 years ago

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MATLAB Basic: rounding IV
Do rounding towards plus infinity. Example: -8.8, answer -8 +8.1 answer 9 +8.50 answer 9

4 years ago

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MATLAB Basic: rounding II
Do rounding nearest integer. Example: -8.8, answer -9 +8.1 answer 8 +8.50 answer 9

4 years ago

Solved

Trimming Spaces
Given a string, remove all leading and trailing spaces (where space is defined as ASCII 32). Input a = ' singular value deco...

4 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...

4 years 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 ...

4 years ago

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MATLAB Basic: rounding
Do rounding near to zero Example: -8.8, answer -8 +8.1 answer 8

4 years ago

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Reverse Run-Length Encoder
Given a "counting sequence" vector x, construct the original sequence y. A counting sequence is formed by "counting" the entrie...

4 years ago