（求循环节的个数）Power Strings -- poj -- 2406

#include<stdio.h>
#include<string.h>
#include<stdlib.h>

#define N 1000007

char S[N];
int Next[N];  

/// Next中存的是前缀和后缀的最大相似度

void FindNext(int Slen, int Next[]) ///Next[i] 代表前 i 个字符的最大匹配度
{
    int i=0, j=-1;
    Next[0] = -1;

    while(i<Slen)
    {
        if(j==-1 || S[i]==S[j])
            Next[++i] = ++j;
        else
            j = Next[j];
    }
}

int main()
{
    while(scanf("%s", S), strcmp(S, "."))
    {
        int Slen=strlen(S);

        FindNext(Slen, Next);

        if(Slen%(Slen-Next[Slen]))
            printf("1\n");
        else
            printf("%d\n", Slen/(Slen-Next[Slen]));
    }

    return 0;
}