HDU 1358 Period

Question link: http://acm.hdu.edu.cn/showproblem.php? PID = 1, 1358

Explanation of output data,

Group 1:

2 2 indicates the first letter to the second letter, and a appears twice.

3 3 indicates the first letter to the third letter, and a appears three times.

Group 2:

2 2 indicates the first letter to the second letter, and a appears twice. 6 2 indicates the first letter to the sixth letter, and AAB appears twice. 9 3 indicates the first letter to the ninth letter, and AAB appears three times. 12 4 indicates the first letter to 12th letters, and AAB appears four times.

 1 #include <iostream> 2 #include <cstdio> 3 #include <cstring> 4  5 using namespace std; 6  7 int next[1000010]; 8 char str[1000010]; 9 10 void get_next()11 {12     int i=0,j=-1;13     next[0]=-1;14     int lens=strlen(str);15     while (i<lens)16     {17         if (j==-1||str[i]==str[j])18         {19             i++;20             j++;21             next[i]=j;22             if (i>=2&&j>=1)23             {24                 if (i%(i-next[i])==0)25                 {26                     int k=i/(i-next[i]);27                     printf ("%d %d\n",i,k);28                 }29             }30         }31         else32             j=next[j];33     }34 }35 int main ()36 {37     int n,flag=1;38     while (scanf("%d",&n),n)39     {40         getchar();41         scanf("%s",str);42         printf ("Test case #%d\n",flag++);43         get_next();44         printf ("\n");45         //lens=strlen(str);46     }47     return 0;48 }