fsharp-learning/exercism/fsharp/darts/Darts.fs

module Darts

let withinCircle (radius: int) (x: double) (y: double) =
    sqrt ((pown x 2) + (pown y 2)) <= double(radius)

let score (x: double) (y: double): int =
    if withinCircle 10 x y then
        if withinCircle 5 x y then
            if withinCircle 1 x y then
                10
            else
                5
        else
            1
    else 0