lavos/cap3/ex30.go

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
    }
}