hdu 1164 Eddy's research I 素数筛选法 

 1 #include <stdio.h>
 2 #include <string.h>
 3 #include <stdlib.h>
 4 #include <math.h>
 5 
 6 int A[80000], dp[20000];
 7 
 8 const int inf = 65535;
 9 
10 int prime( )
11 {
12     int i, j, k = 0;
13     A[1] = 1;
14     for( i = 2; i <= sqrt(inf); i++)
15        for ( j = 2 * i; j <= inf; j += i)
16            A[j] = 1;
17     for( i = 1; i <= inf; i++)
18         if(!A[i])
19             dp[k++] = i;
20     return k;
21 }
22 
23 int main( )
24 {    
25      int N, i, j, k, cnt;
26      
27      k = prime( );
28      while(scanf("%d", &N) != EOF) {
29         if(N == 0)
30             continue;
31          cnt = 0;
32          
33         for(i = 0; i < k; i++) {
34             while((N%dp[i]) == 0) {
35                 if(cnt)
36                   printf("*");
37                 printf("%d",dp[i]);
38                 cnt++;
39                 N = N / dp[i];
40                 if (N == 1)
41                     break;
42             }
43         }
44         puts("");
45     }
46     return 0;
47 }
48

　　

posted on 2011-07-20 10:21  more think, more gains  阅读(149)  评论(0)  编辑  收藏  举报

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