Problem 3 - Largest prime factor

The prime factors of 13195 are 5, 7, 13 and 29.

What is the largest prime factor of the number 600851475143 ?

求600851475143的最大素数因子。

Python 
 1 factors = []
 2 maximum = 600851475143 
 3 def getFactor(x):
 4     y = x / 2
 5     i = 2
 6     while True:
 7         if i > y:
 8             break
 9         if x % i == 0 :
10             factors.append(i)
11             return getFactor(x / i)
12             break
13         i += 1
14     return x
15 
16 factors.append(getFactor(maximum))
17 
18 print factors[-1]

 

posted on 2013-01-06 08:47  luchigster  阅读(128)  评论(0)  编辑  收藏  举报

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