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Polite numbers. Politeness.
A polite number is an integer that sums of two or more consecutive positive integers. Politeness of a positive integer is a num...

3 years ago

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Number Persistence
A number's persistence is the number of steps required to reduce it to a single digit by multiplying all its digits to obtain a ...

3 years ago

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Miles to go before I sleep
Recently, my car's odometer passed 56789. Given an odometer reading, output how many miles need to be driven to get the next mi...

3 years ago

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Lowest sum from a group of digits
Hi there. It's James's daughter here again, and my third grade math teacher is up to her old tricks. This time, she's giving u...

3 years ago

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Longest Sequence of NaNs
In an array return the length of longest sequence of nans for each column. x = [ 2 3 1 2 5 6; nan nan 5 n...

3 years ago

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Generate a Parasitic Number
This problem is the next step up from Problem 156. Rather than determining if an input is a parasitic number, you will be asked ...

3 years ago

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I've got the power! (Inspired by Project Euler problem 29)
Consider all integer combinations of a^b and b^a for the integer values 2 ≤ a ≤ 4 and 2 ≤ b ≤ 5: 2^2=4, 2^3=8, 2^4=16,...

3 years ago

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Genome decoding
Inspired by a question on the answer forum: You are given a matrix of 8-bit integers which encodes a genome. Each integer can...

3 years ago

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Implement a counter
Write a function that returns a function that counts the number of times it is invoked. Example: >> h = counter; >> h() ...

3 years ago

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Cat, Meowcat and Concatenation
Input is a cell array containing several strings. Find the largest continuous sub-string common to all strings. All strings are ...

3 years ago

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Change Vector Value
Change the element of the vector with respect to the element of the direction vector If the element of the direction vecto...

3 years ago

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nth Rational Number
Return the nth rational number. This is the inverse to Problem <http://www.mathworks.com/matlabcentral/cody/problems/1471 1...

3 years ago

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Polite numbers. N-th polite number.
A polite number is an integer that sums of at least two consecutive positive integers. For example _7 = 3+4_ so 7 is a polite...

3 years ago

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Remove the air bubbles
Given a matrix a, return a matrix b in which all the zeros have "bubbled" to the top. That is, any zeros in a given column shoul...

3 years ago

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Highly divisible triangular number (inspired by Project Euler 12)
Triangular numbers can be calculated by the sum from 1 to n. For example, the first 10 triangular numbers are: 1, 3, 6, 10, ...

3 years ago

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Recurring Cycle Length (Inspired by Project Euler Problem 26)
Preface: This problem is inspired by <http://projecteuler.net/problem=26 Project Euler Problem 26> and uses text from that quest...

3 years ago

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Numbers spiral diagonals (Part 1)
Inspired by Project Euler n°28 et 58. A n x n spiral matrix is obtained by starting with the number 1 and moving to the right...

3 years ago

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Bell Number calculator
Calculate a vector of Bell numbers for sets up to length n. Bell numbers are the maximum number of partitions of a set. See the ...

3 years ago

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Find the minimum of the column-maximums of a matrix
Given a matrix A, find the maximum value of each column, then return the smallest of those maximum values (ie return the minimum...

3 years ago

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Calculate the mean of each half of a matrix
Given a matrix with an even number of columns, n, return a 1-by-2 row vector where the first element is the mean of all the elem...

3 years ago

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Find Closest Constant
Given a number x, return the value that is closest to x from this list of constants: 0, 1, , e, , (also known as ). For exampl...

3 years ago

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Matrix Quadrants
Write a function that takes N as the input, and outputs a matrix whose upper-left (NxN) quadrant contains all ones, the lower-ri...

3 years ago

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Generate this matrix
Generate the following matrix. n = 2; out = [-4 -3 -2 -1 0 -3 -2 -1 0 1 -...

3 years ago

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Sums of cubes and squares of sums
Given the positive integers 1:n, can you: 1. Compute twice the sum of the cubes of those numbers. 2. Subtract the square...

3 years ago

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Birthday cake
It's Cody's 5th birthday, and you've been tasked with putting the candles on the cake. Your goal is to maximize the distance bet...

3 years ago

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Divisors for big integer
Inspired by Problem 1025 and Project Euler 12. Given n, return the number y of integers that divide N. For example, with ...

3 years ago

Solved

Numbers spiral diagonals (Part 2)
Inspired by Project Euler n°28 and 58. A n x n spiral matrix is obtained by starting with the number 1 and moving to the right ...

3 years ago

Solved

Draw a 'Z'.
Given _n_ as input, generate a n-by-n matrix like 'Z' by _0_ and _1_ . Example: n=5 ans= [1 1 1 1 1 0 0 0 1 ...

3 years ago

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Draw a 'X'!
Given n as input Draw a 'X' in a n-by-n matrix. example: n=3 y=[1 0 1 0 1 0 1 0 1] n=4 y=[1 0 0...

3 years ago

Solved

Draw 'O' !
Given n as input, generate a n-by-n matrix 'O' using 0 and 1 . example: n=4 ans= [1 1 1 1 1 0 0 1 ...

3 years ago