五分钟捡起Python妥妥的 

 1 import math
 2 
 3 def primeFactor(source):
 4     start = int(math.floor(math.sqrt(source)))
 5     
 6     while start > 1:
 7         print start
 8         mod = source % start
 9         if mod == 0 and isPrime(start):
10             return start
11         start -= 1
12         
13 def isPrime(source):
14     start = source / 2
15     
16     while start > 1:
17         if source % start == 0:
18             return False
19         start -= 1
20         
21     return True
22         
23     
24 print primeFactor(600851475143)
妥
 1 import java.math.BigInteger;
 2 
 3 public class test {
 4     public static void main(String[] args) {
 5         System.out.println(primeFactor("600851475143"));
 6     }
 7     
 8     public static long primeFactor(String source) {
 9         BigInteger src = new BigInteger(source);
10         long start = (long) src.divide(new BigInteger("2")).longValue();
11         
12         for (long number = start; number > 0; number--) {
13             System.out.println(number);
14             long module = src.mod(BigInteger.valueOf(number)).longValue();
15             if (module == 0 && isPrime(number))
16                 return number;
17         }
18         
19         return -1;
20     }
21     
22     public static boolean isPrime(long source) {
23         long start = (long) Math.floor(source / 2);
24         
25         for (long number = start; number > 1; number--) {
26             long module = source % number;
27             if (module == 0)
28                 return false;
29         }
30         return true;
31     }
32 }
不妥

前边的一分钟查忘记的语法，四分钟写代码，十秒出答案。

后边的写了一个多小时现在还在算。谁告诉我BigInteger怎么开房不开方。

posted @ 2013-12-05 22:36  Chihane  阅读(145)  评论(0)  编辑  收藏  举报