C++ :

#include <iostream>
#include <cstring>
#include <stdio.h>
#include <stdlib.h>
#include <algorithm>
using namespace std;

const int N = 1000002;
int Next[N];
char S[N], T[N];
int slen, tlen;

void getNext()
{
    int j, k;
    j = 0; k = -1; Next[0] = -1;
    while(j < tlen)
        if(k == -1 || T[j] == T[k])
            Next[++j] = ++k;
        else
            k = Next[k];

}
/*
返回模式串在主串S中出现的次数
*/
int KMP_Count()
{
    int ans = 0;
    int i, j = 0;
    if(slen == 1 && tlen == 1)
    {
        if(S[0] == T[0])
            return 1;
        else
            return 0;
    }
    for(i = 0; i < slen; i++)
    {
        while(j > 0 && S[i] != T[j])
            j = Next[j];
        if(S[i] == T[j])
            j++;
        if(j == tlen)
        {
            ans++;
            j = Next[j];
        }
    }
    return ans;
}
int main()
{
    scanf("%s",S);
    scanf("%s",T);
    slen = strlen(S);
    tlen = strlen(T);
    getNext();
    printf("%d\n",KMP_Count());
    return 0;
}