题解 | #三角形判断#

while True:
    try:
        num = list(map(int, input().split()))
        num .sort()
        if num[0] + num[1] <= num[2]:  # 两短边之和小于第三遍，三角形不成立
            print("Not a triangle!")
        elif num[0] == num[1] and num[1] != num[2]: # 两边相等但不等于第三边
            print("Isosceles triangle!")
        elif num[1] == num[2] and num[1] != num[0]:
            print("Isosceles triangle!")
        elif num[0] == num[1] == num[2]:  # 三边相等
            print("Equilateral triangle!")
        else:
            print("Ordinary triangle!")
    except:
        break

注意过滤顺序