CODEWITHSUNDEEP
haskell
Joel
Joel

Reputation: 6107

Generating a list of numbers with Haskell

A Pythagorean triplet is a set of three natural numbers, a < b < c, for which, a^(2) + b^(2) = c^(2). There exists exactly one Pythagorean triplet for which a + b + c = 1000.

I am trying to generate a list with the answer:

[200,375,425]

For that, I programmed in Haskell:

p = [ [a, b, c] | b <- [1..1000], a <- [1..b], let c = 1000 - b - a, a^2 + b^2 == c^2 && b<c]

This generates 

[[200,375,425]]

How can I change my solution to generate the first output (instead of the one I have now)?

Upvotes: 1

Views: 2014

Answers (2)

Retief
Retief

Reputation: 3217

Look at your output. It generated a list whose first result is the result you want. There's a function that takes a list and returns the first element -- head. Call head on the output from your existing code, and you will get the result you want.

Upvotes: 4

Abhinav Sarkar
Abhinav Sarkar

Reputation: 23812

head $ [ [a, b, c] | b <- [1..1000], a <- [1..b], let c = 1000 - b - a, a^2 + b^2 == c^2 && b<c]

Upvotes: 3

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