HDU-2087-KMP-水题

纯KMP

#include <cstdio>
#include <algorithm>
#include <cstring>
#include <ctype.h>
#include <cstdlib>
#include <stack>
#include <set>
#include <map>
#include <queue>
#include <string>
#include <cmath>



using namespace std;

int M,N,T;
char A[1000100],B[10100];
int f[10100];

void getFail(char *P)
{        
    f[0] = 0;f[1] = 0;
    for(int i=1;i<M;i++)
    {
        int j = f[i];
        while(j && P[i] != P[j]) j = f[j];
        f[i+1] = P[i] == P[j] ? j+1 : 0;
    }
}

int find(char *T,char *P)
{
    getFail(P);
    int j=0;
    int ans = 0;
    for(int i=0;i<N;i++)
    {
        while(j && T[i] != P[j]) j = f[j];
        if( T[i] == P[j] ) j++;
        if(j == M) {i += M-1;ans++;}
    }
    return ans;
}


int main()
{
    
    while(2 == scanf("%s %s",A,B))
    {
        N = strlen(A);M = strlen(B);
        printf("%d
",find(A,B));
    }
}