ProjectEuler-Problem 3-Largest prime factor

# @Time    : 2017/6/18 10:03# @Author  : wanyang# @Mail    ：[e-mail]# @Question：Largest prime factor https://projecteuler.net/problem=3# @Answer  ：6857from math import *# 判断是否是质数def is_prime(num):    for i in range(2, int(sqrt(num)) + 1):        if num % i == 0:            return False    return True# 递归调用，获取质因数def prime_factor(num):    if is_prime(num):        print(num)        return num    for i in range(2, int(sqrt(num)) + 1):        if num % i == 0:            print(i)            prime_factor(int(num / i))            return# number = 13195number = 600851475143prime_factor(number)