POJ2406(next原理理解)

#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;
const int MAXN=1000005;
char s[MAXN];
int len;
int next[MAXN];
void getnext()
{
    int i=0,k=-1;
    next[0]=-1;
    while(i<len)
    {
        if(k==-1||s[i]==s[k])
        {
            i++;
            k++;
            next[i]=k;
        }
        else    k=next[k];
    }
}
int main()
{
    while(gets(s)&&*s!=‘.‘)
    {
        len=strlen(s);
        getnext();
        int ans=1;
        if(len%(len-next[len])==0)    ans=len/(len-next[len]);
        printf("%d\n",ans);
    }
    
    return 0;
}