poj 3461 Oulipo

 1 #include<cstdio>
 2 #include<cstring>
 3 using namespace std;
 4 const int maxn=1e6+10;
 5 
 6 char T[maxn],P[maxn];
 7 int t,next[maxn];
 8 
 9 void getnext()
10 {
11     int m=strlen(P+1);
12     next[1]=0;
13     for(int k=0,q=2;q<=m;q++){
14         while(k>0&&P[k+1]!=P[q]) k=next[k];
15         if(P[k+1]==P[q]) k++;
16         next[q]=k;
17     }
18 }
19 
20 int KMP()
21 {
22     int n=strlen(T+1);
23     int m=strlen(P+1);
24     int sum=0;
25     getnext();
26     for(int k=0,q=1;q<=n;q++){
27         while(k>0&&P[k+1]!=T[q]) k=next[k];
28         if(P[k+1]==T[q]) k++;
29         if(k==m){
30             sum++;
31             k=next[k];
32         }
33     }
34     return sum;
35 }
36 
37 int main()
38 {
39     scanf("%d",&t);
40     while(t--)
41     {
42         scanf("%s%s",P+1,T+1);
43         printf("%d\n",KMP());
44     }
45     return 0;
46 }