KMP算法模板

 

#include <cstdio>
#include <cstring>
using namespace std;
#define N 10010
#define M 1000010

char S[M], T[N];
int next[N];

void Get_next()
{
    int i=0, j=-1;
    next[0] = -1;
    int lt = strlen(T);
    while(i<lt)
    {
        if(j==-1 || T[i]==T[j])
            next[++i] = ++j;
        else j = next[j];
    }
}

int KMP()
{
    int i=0, j=0, cnt=0;
    int ls = strlen(S), lt=strlen(T);
    Get_next();
    while(i<ls && j<lt)
    {
        if(S[i]==T[j] || j==-1)
            i++, j++;
        else
            j = next[j];
        if(j==lt) //得到一个子串
        {
            cnt++;
            j = next[j];
        }
    }
    return cnt;
}

int main()
{
    int n;
    while(~scanf("%d", &n))
    {
        for(int i=0; i<n; i++)
        {
            scanf("%s%s", T, S);
            printf("%d\n", KMP());
        }
    }
    return 0;
}