KMP UVA1328 Period

https://vjudge.net/problem/UVA-1328

KMP求循环节的问题

 1 #include<iostream>
 2 #include<cstdio>
 3 #include<cstring>
 4 #include<algorithm>
 5 using namespace std;
 6 int n,l,j,cnt,et;
 7 char s[1000010];
 8 int nt[1000010];
 9 int main(){ 
10     while(scanf("%d",&n)==1&&n){
11         scanf("%s",s+1);
12         j=0;
13         for(int i=2;i<=n;i++){
14             while(j&&s[j+1]!=s[i]) j=nt[j];
15             j+=(s[j+1]==s[i]);
16             nt[i]=j;
17         }
18         printf("Test case #%d
",++cnt);
19         for(int i=2;i<=n;i++)
20             if(nt[i]>0&&(i%(i-nt[i])==0)) printf("%d %d
",i,i/(i-nt[i]));
21         printf("
");
22     }
23     return 0;
24 }