package pythagorean

import "math"

type Triplet [3]int

func isTriplet(a, b, c int) bool {
    return a*a + b*b == c*c && a < b && b < c
}

func Range(min, max int) []Triplet {
    var triplets = []Triplet{}
    for c := min; c <= max; c++ {
        for b := min; b <= c - 1; b++ {
            a := int(math.Sqrt(float64(c*c - b*b)))

            if isTriplet(a, b, c) && a >= min {
                triplets = append(triplets, Triplet{a,b,c})
            }
        }
    }
	return triplets
}

func Sum(p int) []Triplet {
    temp_triplets := Range(1, p / 2)
    triplets := make([]Triplet, 0, len(temp_triplets))

    for _, triplet := range temp_triplets {
        if triplet[0] + triplet[1] + triplet[2] == p {
            triplets = append(triplets, triplet)
        }
    }
    // Reverse slice..
    for i, j := 0, len(triplets)-1; i < j; i, j = i+1, j-1 {
        triplets[i], triplets[j] = triplets[j], triplets[i]
    }
	return triplets
}