POJ 1961 Period（KMP)

题目链接

和POJ2406差不多，不过用暴力去找，会超时。

 1 #include <stdio.h>
 2 #include <string.h>
 3 #include <math.h>
 4 #define N 1000001
 5 char str[N];
 6 int next[N];
 7 int main()
 8 {
 9     int i,j,len,d,a = 0;
10     while(scanf("%d%*c",&len)!=EOF)
11     {
12         a ++;
13         if(len == 0)break;
14         scanf("%s",str);
15         memset(next,0,sizeof(next));
16         if(str[0] == '.')break;
17         next[0] = -1;
18         j = -1;
19         for(i = 1; i <= len-1; i ++)
20         {
21             while(j >= 0&&str[j+1] != str[i])
22                 j = next[j];
23             if(str[j+1] == str[i]) j++;
24             next[i] = j;
25         }
26         printf("Test case #%d\n",a);
27         for(j = 1; j <= len; j ++)
28         {
29             d = j-1-next[j-1];
30             if(j % d == 0&&j/d != 1)
31             printf("%d %d\n",j,j/d);
32         }
33         printf("\n");
34     }
35     return 0;
36 }
posted @ 2012-07-20 13:44  Naix_x  阅读(174)  评论(0)  编辑  收藏  举报