Oulipo

 1 #include<cstdio>
 2 #include<cstdlib>
 3 #include<cstring>
 4 #define N 1000005
 5 using namespace std;
 6 int next[N];
 7 char s1[N],s2[N];
 8 int len1,len2,ans;
 9 void getnext(int plen){
10     int i = 0,j = -1;
11     next[0] = -1;
12     while( i<plen ){
13         if(j==-1||s1[i]==s1[j]){
14             ++i;++j;
15           if(s1[i]!=s1[j] )
16             next[i] = j;
17           else
18             next[i] = next[j];
19         }
20         else
21             j = next[j];
22     }
23 }
24 void KMP(){
25     getnext(len1);
26     int i = 0,j = 0;
27     while (i<len2&&j<len1){
28         if( j == -1 || s2[i] == s1[j] ){
29             ++i;
30             ++j;
31         }
32         else {
33             j = next[j];
34 
35         }
36          if( j==len1 ){//找到一个匹配串之后，不是在原来串中往后移动一位，而是移动i-(j-next[j]);
37             ans++;
38             j=next[j];
39          }
40     }
41 }
42 int main(){
43     int k;
44     scanf("%d",&k);
45     while(k--){
46         scanf("%s%s",s1,s2);
47         len1=strlen(s1);
48         len2=strlen(s2);
49         ans=0;
50         KMP();
51         printf("%d\n",ans);
52     }
53 }