HDOJ HDU 1164 Eddy's research I ACM 1164 IN HDU

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题目地址:
         http://acm.hdu.edu.cn/showproblem.php?pid=1164
题目描述:
         把一个数拆分成素数的乘积.

素数的水题 ,  只要把素数提取出来, 暴力就可以了.
代码如下 :

//MiYu原创, 转帖请注明 : 转载自 ______________白白の屋

#include <iostream>
using namespace std;
int num[70001];
int main ()
{
    for ( int i = 2; i <= 70000; ++ i )
    {
          if ( !num[i] )
          for ( int j = 2; i * j <= 70000; ++ j )
          {
                num[i*j] = 1; 
          } 
    }
    int N;
    while ( cin >> N )
    {
           int n = N;
           int f = 1;
           while ( n != 1 )
           {     
                  int i = 2;
                  for ( ; i <= 65535; ++ i )
                  {
                        if ( !num[i] && n % i == 0 )
                        {
                              if ( f )
                              {
                                   cout << i; 
                                   f = 0;
                              }
                              else
                              {
                                   cout << "*" << i; 
                              }
                              break;
                        } 
                  } 
                  n /= i;
           } 
           cout << endl;
    }
//    getchar();
    return 0; 
}