Problem

Nilpotent matrix
Check if matrix A is <http://mathworks.com/ nilpotent>.

14 years ago | 1 | 317 solvers

Solved

vectorization in N
For a given integer n (n>1), compute the sum f (i) (1 <= i <= n) where f (i) = 1 if n is odd and 2 otherwise.

14 years ago

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Tricky timing
Write a function that takes between 0.5 seconds and 0.6 seconds to run.

14 years ago

Solved

Woodall number
Test whether the input is a Woodall number: <http://en.wikipedia.org/wiki/Woodall_number> _Please do not cheat by simply chec...

14 years ago

Answered
contourlines in time format
It may be helpful to Analyze this code: Z = 5+abs(peaks)/10; [C,h] = contour(interp2(Z,4)); th = clabel(C,h); set(...

14 years ago | 0

Answered
How to create non-repetitive random integers
Try this code: N = 100; x = randperm(N); x = x(1:70)

14 years ago | 0

| accepted

Solved

Return the 'Size' of a String of Code
One of the most 'mysterious' parts of playing Cody is the sizing system. Given a string of commands, return the size that Cody w...

14 years ago

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deconvolution
* Suppose there is a vector v like [1 0 0 -1], representing polynomial coefficients. * In this example, the polynimial is 1*x^3...

14 years ago

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Whether the input is vector?
Given the input x, return 1 if x is vector or else 0.

14 years ago

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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...

14 years ago

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

14 years ago

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Filter AC, pass DC
Input x is the sampled signal vector, may have both AC and DC components. Output vector y should not contain any AC component. ...

14 years ago

Solved

Project Euler: Problem 7, Nth prime
By listing the first six prime numbers: 2, 3, 5, 7, 11, and 13, we can see that the 6th prime is 13. What is the Nth prime nu...

14 years ago

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More luck than brains
Give a random function that guess and return numbers from 1 to 6 exactly like the test suite .

14 years ago

Solved

Is A the inverse of B?
Given a matrix A and a matrix B, is A the inverse of B? >>A=[2,4;3,5]; >>B=[-2.5,2;1.5,-1]; >>isInverse...

14 years ago

Solved

Check to see if a Sudoku Puzzle is Solved
*Description:* Your task, should you choose to accept it, is to make a function that checks to see if a 9x9 matrix of integer...

14 years ago

Solved

pressure to dB?
given x ratio of pressure, find corresponding y dB

14 years ago

Solved

Counting in Finnish
Sort a vector of single digit whole numbers alphabetically by their name, in Finnish. See the Wikipedia page for <http://en.wik...

14 years ago

Problem

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 ...

14 years ago | 6 | 1452 solvers

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 ...

14 years ago

Solved

Scrabble Scores
Given a word, determine its score in <http://en.wikipedia.org/wiki/Scrabble Scrabble>. The input string will always be provide...

14 years ago

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Scoring for oriented dominoes
Given a list of ordered pairs, and the order they should be placed in a line, find the sum of the absolute values of the differe...

14 years ago

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Renaming a field in a structure array
MATLAB has a <http://www.mathworks.com/help/techdoc/ref/setfield.html setfield> and a <http://www.mathworks.com/help/techdoc/ref...

14 years ago

Solved

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...

14 years ago

Solved

Count from 0 to N^M in base N.
Return an array of numbers which (effectively) count from 0 to N^M-1 in base N. The result should be returned in a matrix, with ...

14 years ago

Solved

Project Euler: Problem 6, Natural numbers, squares and sums.
The sum of the squares of the first ten natural numbers is, 1^2 + 2^2 + ... + 10^2 = 385 The square of the sum of the first ...

14 years ago

Solved

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...

14 years ago

Solved

Implement a ROT13 cipher
Replace each character in string s1 with the character that is shifted 13 positions from it (wrap back to the beginning if neces...

14 years ago

Solved

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 ...

14 years ago

Solved

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...

14 years ago