package pythagorean_test
// Use this type definition,
//
//    type Triplet [3]int
//
// and implement two functions,
//
//    Range(min, max int) []Triplet
//    Sum(p int) []Triplet
//
// Range returns a list of all Pythagorean triplets with sides in the
// range min to max inclusive.
//
// Sum returns a list of all Pythagorean triplets where the sum a+b+c
// (the perimeter) is equal to p.
//
// The three elements of each returned triplet must be in order,
// t[0] <= t[1] <= t[2], and the list of triplets must be in lexicographic
// order.
import (
	"pythagorean"
	"reflect"
	"testing"
)
var rangeTests = []struct {
	min, max int
	ts       []pythagorean.Triplet
}{
	{1, 10, []pythagorean.Triplet{{3, 4, 5}, {6, 8, 10}}},
	{11, 20, []pythagorean.Triplet{{12, 16, 20}}},
}
func TestRange(t *testing.T) {
	for _, test := range rangeTests {
		ts := pythagorean.Range(test.min, test.max)
		if !reflect.DeepEqual(ts, test.ts) {
			t.Fatalf("Range(%d, %d) = %v, want %v",
				test.min, test.max, ts, test.ts)
		}
	}
}
var sumTests = []struct {
	sum int
	ts  []pythagorean.Triplet
}{
	{180, []pythagorean.Triplet{{18, 80, 82}, {30, 72, 78}, {45, 60, 75}}},
	{1000, []pythagorean.Triplet{{200, 375, 425}}},
}
func TestSum(t *testing.T) {
	for _, test := range sumTests {
		ts := pythagorean.Sum(test.sum)
		if !reflect.DeepEqual(ts, test.ts) {
			t.Fatalf("Sum(%d) = %v, want %v",
				test.sum, ts, test.ts)
		}
	}
}
func BenchmarkRange(b *testing.B) {
	for i := 0; i < b.N; i++ {
		pythagorean.Range(1, 100)
	}
}
func BenchmarkSum(b *testing.B) {
	for i := 0; i < b.N; i++ {
		pythagorean.Sum(1000)
	}
}

// Package pythagorean is for searching Pythagorean triplets.
package pythagorean
// Triplet represent a Pythagorean triplet.
type Triplet [3]int
// Range returns a list of all Pythagorean triplets with sides in the range min to may inclusive.
func Range(min, max int) []Triplet {
	var ret []Triplet
	for a := min; a <= max; a++ {
		for b := a + 1; b <= max; b++ {
			for c := b + 1; c <= max; c++ {
				if a*a+b*b == c*c {
					ret = append(ret, Triplet{a, b, c})
				}
			}
		}
	}
	return ret
}
// Sum returns a list of all Pythagorean triplets where the sum a+b+c is equal to p.
func Sum(p int) []Triplet {
	var ret []Triplet
	candidates := Range(1, p/2)
	for i, tr := range candidates {
		if tr[0]+tr[1]+tr[2] == p {
			ret = append(ret, candidates[i])
		}
	}
	return ret
}