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Mersenne Primes
A Mersenne prime is a prime number of the form M = 2^p - 1, where p is another prime number. For example, 31 is a Mersenne prim...

12 years 前

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Find the largest value in the 3D matrix
Given a 3D matrix, A, find the largest value. E.g. >> A = 1:9; >> A=reshape(A,[3 1 3]); >> islargest(A) ans = 9

12 years 前

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Count photos
Given n people, everyone must have pictures taken with everyone, each photo includes only two persons, please count the total nu...

12 years 前

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Converting Decimal to Binary
Given a decimal number that may include a fractional component, convert it into binary representation. The numbers you are given...

12 years 前

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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...

12 years 前

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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...

12 years 前

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Back to basics 26 - Keywords
Covering some basic topics I haven't seen elsewhere on Cody. Return a cell array of strings of all MATLAB keywords.

12 years 前

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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

12 years 前

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Replace May with April
For instance, if the input is input_str = 'The flowers may bloom in April'; then the output is output_str = 'The flo...

12 years 前

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resistor ladder
* You have a bunch (an odd number N) of identical resistors (each R ohms), a good battery (V volts), and a high impedance voltme...

12 years 前

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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...

12 years 前

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Person of interest?
given a person_of_interest, what is his_name?

12 years 前

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cos for boss?
a programmer had too much coffee and his boss needs cos(alpha+beta) correctly, especially when alpha or beta or the coffee are c...

12 years 前

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Einsteinium-253 decay
Radioactive Einsteinium-253 has a half-life of 1,768,608 seconds. Given 1000mg of Einsteinium-253 at t=0 days, how much is lef...

12 years 前

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Angle between two vectors
You have two vectors , determine the angle between these two vectors For example: u = [0 0 1]; v = [1 0 0]; The a...

12 years 前

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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...

12 years 前

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Back to basics 22 - Rotate a matrix
Covering some basic topics I haven't seen elsewhere on Cody. Rotate the input matrix 90 degrees counterclockwise (e.g. [1 2; ...

12 years 前

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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...

12 years 前

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Back to basics 20 - singleton dimensions
Covering some basic topics I haven't seen elsewhere on Cody. Remove the singleton dimensions from the input variable (e.g. if...

12 years 前

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Back to basics 19 - character types
Covering some basic topics I haven't seen elsewhere on Cody. Return the number of punctuation characters in the input variabl...

12 years 前

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Back to basics 18 - justification
Covering some basic topics I haven't seen elsewhere on Cody. Given a string with extra spaces in front and/or in back, return...

12 years 前

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Back to basics 17 - white space
Covering some basic topics I haven't seen elsewhere on Cody. Remove the trailing white spaces from the input variable

12 years 前

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Back to basics 16 - byte order
Covering some basic topics I haven't seen elsewhere on Cody. Switch the byte order of the input (i.e. if little-endian -> big...

12 years 前

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Dancing with wolves?
let wolf() make one or two steps to get a feel of the beat, it is waltz, do not let wolf() make the third step, return safely ju...

12 years 前

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Back to basics 15 - classes
Covering some basic topics I haven't seen elsewhere on Cody. Return the class of the input variable.

12 years 前

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Decimal Comparison
*Background* A utility of particular interest to Cody and other MATLAB ventures is comparing the equality of two numbers. In ...

13 years 前

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commutative?
Given the handle to a binary function that takes two ordinary numbers, test if the function is commutative.

13 years 前

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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...

13 years 前

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Matrix spiral
Make a spiral in a (n*n) matrix. The spiral has to start in the top left, and has to rotate clockwise to the center. The spiral ...

13 years 前

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peta to nano (x-ray)
for certain x-ray radiation, given frequency in petahertz, give wavelength in nanometer, must be accurate +/- 25%

13 years 前