hdu 2203 亲和串 kmp

#include <bits/stdc++.h>
#define PB push_back
#define MP make_pair
using namespace std;
typedef long long LL;
typedef pair<int,int> PII;
#define PI acos((double)-1)
#define E exp(double(1))
#define K 1000000+9
int nt[K];
string sa,sb;
void kmp_next(void)
{
    nt[0]=0;
    for(int i=1,j=0,len=sb.length();i<len;i++)
    {
        while(j&&sb[j]!=sb[i])j=nt[j-1];
        if(sb[j]==sb[i])j++;
        nt[i]=j;
    }
}
int kmp(void)
{
    kmp_next();
    for(int i=0,j=0,lena=sa.length(),lenb=sb.length();i<lena;i++)
    {
        while(j&&sa[i]!=sb[j])j=nt[j-1];
        if(sa[i]==sb[j])j++;
        if(j==lenb)
            return 1;
    }
    return 0;
}
int main(void)
{
    while(cin>>sa>>sb)
    {
        sa+=sa;
        if(kmp())
            printf("yes\n");
        else
            printf("no\n");
    }

    return 0;
}