Period---hdu1358（循环节 kmp）

#include<stdio.h>
#include<iostream>
#include<algorithm>
#include<string.h>
using namespace std;

const int N = 1e6+7;

char s[N];
int Next[N], n;

void GetNext()
{
    int i=0, j=-1;
    Next[0] = -1;
    while(i<n)
    {
        if(j==-1 || s[i] == s[j])
            Next[++i] = ++j;
        else
            j=Next[j];
    }
}
int main()
{
    int t=1;
    while(scanf("%d", &n),n)
    {
        scanf("%s", s);
        GetNext();
        printf("Test case #%d\n", t++);
        for(int i=2; i<=n; i++)
        {
            int Min_cycle = i - Next[i];
            if(i%Min_cycle==0 && i/Min_cycle != 1)///题中说了循环k次， k > 1的
                printf("%d %d\n", i, i/Min_cycle);
        }
        printf("\n");
    }
    return 0;
}