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...

plus d'un an ago

Solved

Calculate the area of a triangle between three points

Calculate the area of a triangle between three points: P1(X1,Y1) P2(X2,Y2) P3(X3,Y3) these three points are the vert...

plus d'un an ago

Solved

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 ...

plus d'un an ago

Solved

Solitaire Cipher

Implement the <http://en.wikipedia.org/wiki/Solitaire_(cipher) solitaire cipher>. Since this is from Wikipedia, I am capturin...

plus d'un an ago

Solved

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...

plus d'un an ago

Solved

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 ...

plus d'un an ago

Solved

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 ...

plus d'un an ago

Solved

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...

plus d'un an ago

Solved

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 ...

plus d'un an ago

Solved

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...

plus d'un an ago

Solved

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...

plus d'un an ago

Solved

Reverse the elements of an array

Reverse the order of elements in an array: eg: input X = [ 1 2 3 ; 4 5 6 ; 7 8 9 ] o...

plus d'un an ago

Solved

Permute diagonal and antidiagonal

Permute diagonal and antidiagonal For example [1 2 3;4 5 6;7 8 9] -> [3 2 1;4 5 6;9 8 7] WITHOUT diag function (and variable n...

plus d'un an ago

Solved

Rotate input square matrix 90 degrees CCW without rot90

Rotate input matrix (which will be square) 90 degrees counter-clockwise without using rot90,flipud,fliplr, or flipdim (or eval)....

plus d'un an ago

Solved

Removing rows from a matrix is easy - but what about inserting rows?

Assume A is a 5-by-5 matrix. A([2,4],:) = [] is a quick way to remove rows 2 and 4. Can you find a quick way to insert rows into...

plus d'un an ago

Solved

Matrix with different incremental runs

Given a vector of positive integers a = [ 3 2 4 ]; create the matrix where the *i* th column contains the vector *1:a(i)...

plus d'un an ago

Solved

Set some matrix elements to zero

First get the maximum of each *row*, and afterwards set all the other elements to zero. For example, this matrix: 1 2 3 ...

plus d'un an ago

Solved

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...

plus d'un an ago

Solved

surrounded matrix

With a given matrix A (size m x n) create a matrix B (size m+2 x n+2) so that the matrix A is surrounded by ones: A = [1 2 ...

plus d'un an ago

Solved

Flip the main diagonal of a matrix

Given a n x n matrix, M, flip its main diagonal. Example: >> M=magic(5); >> flipDiagonal(M) 9 24 1 ...

plus d'un an ago

Solved

Make an awesome ramp for a tiny motorcycle stuntman

Okay, given a vector, say v=[1 3 6 9 11], turn it into a matrix 'ramp' like so: m=[1 3 6 9 11; 3 6 9 11 0; 6 9 ...

plus d'un an ago

Solved

Back to basics 23 - Triangular matrix

Covering some basic topics I haven't seen elsewhere on Cody. Given an input matrix, return a matrix with all elements above a...

plus d'un an ago

Solved

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...

plus d'un an ago

Solved

Remove NaN ?

input -> matrix (n*m) with at least one element equal to NaN; output -> matrix(p*m), the same matrix where we deleted the enti...

plus d'un an ago

Solved

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...

plus d'un an ago

Solved

Mongean Shuffle : 2

Extension to <https://www.mathworks.com/matlabcentral/cody/problems/2479-mongean-shuffle problem 2479>: Determine the number...

plus d'un an ago

Solved

Mongean Shuffle

A Mongean shuffle of an n card deck starts with putting the initial deck on the left hand side. * The top card of the deck is...

plus d'un an ago

Solved

Card Game

This is an overly simplified and highly modified version of card game Twenty-Nine. A deck of 100 unique cards (hypothetical) ...

plus d'un an 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 ...

plus d'un an ago

Solved

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...

plus d'un an ago