Solved

High school cafeteria
Given an input vector of positive integers, return a row vector with the primes first (in increasing order) and the composites n...

13 years ago

Solved

Distance walked 2D
Suppose you go from x-y coordinates [3,4] to [0,0] to [0,1] to [1,1], then you walked 7 units of distance.

13 years ago

Solved

Find perfect placement of non-rotating dominoes (easier)
Given a list of ordered pairs, find the order they should be placed in a line, such that the sum of the absolute values of the d...

13 years 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...

13 years ago

Solved

middleAsColumn: Return all but first and last element as a column vector
Given input A, return all but the first and last elements, arranged as a column vector. (I.e., all dimensions after the first s...

13 years ago

Solved

Back to basics 13 - Input variables
Covering some basic topics I haven't seen elsewhere on Cody. Return as a string the name of the input variable to the functio...

13 years ago

Solved

Back to basics 3 - Temp Directory
Covering some basic topics I haven't seen elsewhere on Cody. Return a string that is the path to the system's current temp di...

13 years ago

Solved

Matrix indexing with two vectors of indices
Given a matrix M and two index vectors a and b, return a row vector x where x(i) = M(a(i),b(i)).

13 years ago

Solved

The Tower of Hanoi
In the <http://en.wikipedia.org/wiki/Tower_of_Hanoi Tower of Hanoi problem> with 3 rods (1, 2 & 3), the goal is to move a tower ...

13 years ago

Solved

Create a square matrix of multiples
Given an input, N, output a matrix N x N with each row containing multiples of the first element of each row. This also applies...

13 years ago

Solved

Back to basics 24 - Symbolic variables
Covering some basic topics I haven't seen elsewhere on Cody. Given a string algebraic expression, return the symbolic variabl...

13 years ago

Solved

System of equations
Find a solution to a system of equations represented by a |n| by |n+1| matrix. For instance, [ 2 0 4; => 2*x = 4 ...

13 years ago

Solved

First non-zero element in each column
For a given matrix, calculate the index of the first non-zero element in each column. Assuming a column with all elements zero ...

13 years ago

Solved

"mirror" matrix
Create n x 2n "mirror" matrix of this type: e.g. for n = 2 m = [1 2 2 1;1 2 2 1] e.g. for n = 3 m = [1 2 3 3 2 1...

13 years ago

Solved

Getting the absolute index from a matrix
This is a basic MATLAB operation. It is for instructional purposes. --- You may already know how to get the <http://www.ma...

13 years ago

Solved

Geometric series
Find the sum, given the first term t1, the common ratio r, and number of terms n. Examples If input t1=1, r=1, n=7 the...

13 years 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 ...

13 years ago

Solved

Back to basics 25 - Valid variable names
Covering some basic topics I haven't seen elsewhere on Cody. Given a string, return true if it is a valid MATLAB variable nam...

13 years ago

Solved

Rotate a Matrix
Input a Matrix x, Output y is the matrix rotating x 90 degrees clockwise

13 years ago

Solved

Back to basics 5 - Clipboard
Covering some basic topics I haven't seen elsewhere on Cody. Copy the input string to the clipboard

13 years 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 ...

13 years ago

Solved

Sorting
Assume that x is an n-by-2 matrix. The aim is to return the first column of x, but sorted according to the second column. Exa...

13 years ago

Solved

Which quadrant?
Given a complex number, output quadrant 'I' 'II' 'III' or 'IV' | II | I | ...

13 years ago

Solved

Combinations without using nchoosek
You have to generate a matrix with all possible combinations of n elements *taken 2* at a time, *without using nchoosek(1:n,2)* ...

13 years ago

Solved

Covering area
As an extension of the problem <http://www.mathworks.com/matlabcentral/cody/problems/416-polygon-area>, find the area, bounded b...

13 years ago

Solved

Rank of magic square (for beginners)
Compute the rank r of a magic square of order n WITHOUT rank and magic functions.

13 years ago

Solved

Calculate the height of an object dropped from the sky
Assume that an object is dropped from 1000 meters above the surface of the earth at time t=0. The object is dropped such that t...

13 years ago

Solved

The Birthday Phenomenon
First off, leap years are not being considered for this. In fact the year that people are born shouldn't be taken into considera...

13 years ago

Solved

Determine if input is a Narcissistic number
<http://en.wikipedia.org/wiki/Narcissistic_number Narcissistic number> is a number that is the sum of its own digits each raised...

13 years ago

Solved

Convert Hard Drive marketing sizes to actual data sizes
Hard drive sizes are typically marketed using the decimal meaning of prefixes, whereas RAM uses binary meanings. For example: ...

13 years ago