poj 2406 Power Strings

http://poj.org/problem?id=2406

题目同 poj 1961

代码：

#include<iostream>
#include<cstdio>
#include<cstring>
#include<string>
#include<cmath>
#include<queue>
#include<algorithm>
#include<set>

using namespace std;

const int N=1000010;

char s[N];
int next[N];
int ans[N];
void findnext(int n)
{
    int j=-1;
    int i=0;
    next[0]=-1;
    while(i<n)
    {
        if(j==-1||s[i]==s[j])
        {
            ++j;++i;next[i]=j;
        }else
        {
            j=next[j];
        }
    }
}
int main()
{

   int n;
   while(gets(s))
   {
       n=strlen(s);
       if(n==1&&s[0]=='.')
       break;
       findnext(n);
       int l=n-next[n];
       if(next[n]>=n/2&&n%l==0)
       {
           printf("%d\n",n/l);
       }else
       {
           printf("1\n");
       }
   }
   return 0;
}