leetcode--阶乘

给定一个数num，返此数的阶乘。如num=5, result = 120

# -*- coding:utf-8 -*-


def factorial_num(n):
    if n == 0 or n == 1:
        return 1

    total = 1
    while n > 0:
        total *= n
        n -= 1

    return total

print('result:', factorial_num(5))