gistfile1.fs

(* Project Euler Problem 9 
A Pythagorean triplet is a set of three natural numbers, a < b < c, for which,
a2 + b2 = c2

For example, 32 + 42 = 9 + 16 = 25 = 52.

There exists exactly one Pythagorean triplet for which a + b + c = 1000.
Find the product abc.
*)

let getTriplet a b = [a;b;sqrt ((a*a) + (b*b))]

let euler9 = 
    let ans = ref 0.0
    let triplets = ref []
    for i in [1.0..1000.0] do
        for j in [1.0..1000.0] do
            triplets := (getTriplet i j) :: !triplets

    for triplet in !triplets do
        if (List.reduce (+) triplet) = 1000.0 then
            ans := List.reduce (*) triplet
    !ans