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发表于 2017-3-17 19:31:52
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- import math
- #def is_prime(x):
- # """ 判断x是否是质数 """
- # x_sqrt = int(math.sqrt(x))
- # for x_ in range(x_sqrt, 1, -1):
- # if x % x_ == 0:
- # return False
- # return True
- #
- #
- #def get_factor(x):
- # """ 获取x的质数因子 """
- # if is_prime(x):
- # return [x]
- # x_sqrt = int(math.sqrt(x))
- # for x_ in range(x_sqrt, 1, -1):
- # if x % x_ == 0:
- # tmp = get_factor(x_)
- # tmp.extend(get_factor(int(x / x_)))
- # return tmp
- def is_prime(x):
- """ 判断x是否是质数 """
- if x == 2:
- return True
- x_sqrt = int(math.sqrt(x))
- l = [2]
- l.extend(range(3, x_sqrt + 1, 2))
- for i in l:
- if x % i == 0:
- return False
- return True
- def get_factor(x):
- """ 获取x的质数因子 """
- def factor_div(xx):
- """
- 递归求取xx的质数因子
- 若 xx = i * j,xx的质数因子是i和j的质数因子集合
- """
- if is_prime(xx):
- factor.add(xx)
- return factor
- xx_sqrt = int(math.sqrt(xx))
- for i in range(2, xx_sqrt + 1):
- if xx % i == 0:
- if i not in factor:
- factor_div(i)
- j = int(xx / i)
- if j not in factor:
- factor_div(j)
- break
- return factor
- factor = set()
- factor_div(x)
- if x in factor:
- factor.remove(x)
- return factor
- print(max(get_factor(600851475143)))
复制代码
这样改
然后解释下你的,如果按照你的
n = 20
那么余数为0
不会输出任何东西
你的程序有问题 |
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