package cap3

import "math"

type Ex30TriangleType int

const (
	Ex30TriangleTypeNone        Ex30TriangleType = iota // 不是三角形
	Ex30TriangleTypeNormal      Ex30TriangleType = iota // 普通三角形
	Ex30TriangleTypeIsosceles   Ex30TriangleType = iota // 等腰三角形
	Ex30TriangleTypeEquilateral Ex30TriangleType = iota // 等边三角形
	Ex30TriangleTypeRight       Ex30TriangleType = iota // 直角三角形
)

func Ex30(nums []float64) Ex30TriangleType {
	a, b, c := nums[0], nums[1], nums[2]

	if a <= 0 || b <= 0 || c <= 0 || a+b <= c || a+c <= b || b+c <= a {
		return Ex30TriangleTypeNone
	}

	if a == b && b == c {
		return Ex30TriangleTypeEquilateral
	}

	if a == b || a == c || b == c {
		return Ex30TriangleTypeIsosceles
	}

	if math.Pow(a, 2)+math.Pow(b, 2) == math.Pow(c, 2) ||
		math.Pow(a, 2)+math.Pow(c, 2) == math.Pow(b, 2) ||
		math.Pow(b, 2)+math.Pow(c, 2) == math.Pow(a, 2) {
		return Ex30TriangleTypeRight
	} else {
		return Ex30TriangleTypeNormal
	}
}