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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...

10 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

10 years ago

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Roll the Dice!
*Description* Return two random integers between 1 and 6, inclusive, to simulate rolling 2 dice. *Example* [x1,x2] =...

10 years ago

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Finding Perfect Squares
Given a vector of numbers, return true if one of the numbers is a square of one of the other numbers. Otherwise return false. E...

10 years ago

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Cell joiner
You are given a cell array of strings and a string delimiter. You need to produce one string which is composed of each string fr...

10 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...

11 years ago

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Maximum running product for a string of numbers
Given a string s representing a list of numbers, find the five consecutive numbers that multiply to form the largest number. Spe...

11 years ago

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Number of 1s in the Binary Representation of a Number
*Description* Return the number of 1s in the (unsigned integer) binary representation of a number. This function should be ab...

11 years ago

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Increment a number, given its digits
Take as input an array of digits (e.g. x = [1 2 3]) and output an array of digits that is that number "incremented" properly, (i...

11 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...

11 years 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...

11 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...

11 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 ...

11 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 ...

11 years ago

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

11 years ago

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Fibonacci sequence
Calculate the nth Fibonacci number. Given n, return f where f = fib(n) and f(1) = 1, f(2) = 1, f(3) = 2, ... Examples: Inpu...

11 years ago

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All capital?
Are all the letters in the input string capital letters? Examples: 'MNOP' -> 1 'MN0P' -> 0

11 years 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...

11 years ago

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Pattern matching
Given a matrix, m-by-n, find all the rows that have the same "increase, decrease, or stay same" pattern going across the columns...

11 years ago

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Make one big string out of two smaller strings
If you have two small strings, like 'a' and 'b', return them put together like 'ab'. 'a' and 'b' => 'ab' For extra ...

11 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...

11 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...

11 years 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...

11 years 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 ...

11 years 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 =...

11 years ago

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Bottles of beer
Given an input number representing the number of bottles of beer on the wall, output how many are left if you take one down and ...

11 years ago

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Factorize THIS, buddy
List the prime factors for the input number, in decreasing order. List each factor only once, even if the factorization includes...

11 years ago

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Elapsed Time
Given two date strings d1 and d2 of the form yyyy/mm/dd HH:MM:SS (assume hours HH is in 24 hour mode), determine how much time, ...

11 years 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 ...

11 years ago

Solved

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...

11 years ago