KMP算法模板

// bjtu1394.cpp
#include <cstdio>
#include <cstring>
#include <cmath>
#include <cstdlib>
#include <iostream>
#include <algorithm>
#include <vector>
#include <map>
#include <set>
#define out(v) cout << #v << ": " << (v) << endl
#define SZ(v) ((int)(v).size())
using namespace std;
typedef long long LL;

int CS;
char W[10000 + 5];
char T[1000000 + 5];
int LW, LT;
int next[10000 + 5];
void getnext()
{
	next[0] = -1;
	// 算到LW是有必要的，多次匹配时会用到 
	for (int i = 1, j = -1; i <= LW; ++i) {
		while (j != -1 && W[j] != W[i - 1]) j = next[j];
		next[i] = ++j;
	}
}

int main()
{
	scanf("%d", &CS);
	getchar();
	while (CS--)
	{
		gets(W); LW = strlen(W);
		gets(T); LT = strlen(T);
		getnext();
		
		int i = 0, j = 0, cnt = 0;
		while (i < LT)
		{
			while (j != -1 && T[i] != W[j]) j = next[j];
			++i, ++j;
			if (j == LW) {
				++cnt;
				j = next[j];
			}
		}
		printf("%d\n", cnt);
	}
	return 0;
}