hdu2222(Keywords Search)

思路：题目中有若干个模式川和一个主串，问在主串中出现了几种模式串。显然就是模式串构成AC_Tree()，然后再去匹配主串。

因为new 了空间的，所以最后要delete释放。

// #pragma comment(linker, "/STACK:1024000000,1024000000")
#include <iostream>
#include <algorithm>
#include <iomanip>
#include <sstream>
#include <string>
#include <stack>
#include <queue>
#include <deque>
#include <vector>
#include <map>
#include <set>
#include <stdio.h>
#include <string.h>
#include <math.h>
#include <stdlib.h>
#include <limits.h>
using namespace std;
typedef long long LL;
typedef unsigned long long ULL;
typedef pair<int,int> ii;
const int inf = 1 << 30;
const int INF = 0x3f3f3f3f;
const int MOD = 1e9 + 7;
struct node{
	int cnt;
	struct node* fail;
	struct node* nxt[26];
	node(){
		fail = NULL;
		for (int i=0;i<26;i++)
			nxt[i]=NULL;
		cnt = 0;/*中间节点*/
	}
};
struct node* root;
char keyword[55],str[1000005];
/*构建字典树*/
void build(char *str){
	struct node *p=p=root;
	int index;
	for (;*str !='\0';str++){
		index = *str - 'a';
		if (p->nxt[index] == NULL) p->nxt[index] = new node();
		p = p->nxt[index];
	}
	p->cnt++;
}
/*构建失败指针*/
void AC_tree(){
	queue<node*> que;
	root->fail = NULL;
	struct node *p,*tmp;/*i,j*/
	que.push(root);
	while(!que.empty()){
		p = que.front();//i
		que.pop();
		for (int i=0;i<26;i++){
			if (p->nxt[i] != NULL){
				tmp = p->fail;//j
				while(tmp != NULL){
					if (tmp->nxt[i] != NULL){
						p->nxt[i]->fail = tmp->nxt[i];
						break;
					}
					tmp = tmp->fail;
				}
				if (tmp == NULL)
					p->nxt[i]->fail = root;
				que.push(p->nxt[i]);
			}
		}
	}
}
int find(char *str){
	int index;
	int sum = 0;
	struct node *p,*tmp;
	p = root;
	for (;*str!='\0';str++){
		index = *str - 'a';
		while(p->nxt[index] == NULL && p != root)
			p=p->fail;
		p = p->nxt[index];
		if (p == NULL)
			p = root;
		tmp = p;
		while(tmp != root && tmp->cnt != -1){
			sum += tmp->cnt;
			tmp->cnt = -1;
			tmp = tmp->fail;
		}
	}
	return sum;
}
void del(struct node* root){
	for (int i=0;i<26;i++){
		if (root->nxt[i] != NULL)
			del(root->nxt[i]);
	}
	delete root;
}
int main()
{	
	// freopen("in.txt","r",stdin);
	// freopen("out.txt","w",stdout);
	int T, n;
	while(scanf("%d",&T) != EOF){
		while(T--){
			root = new node();
			scanf("%d",&n);
			getchar();
			while(n--){
				scanf("%s",keyword);
				build(keyword);
			}
			AC_tree();
			scanf("%s",str);
			printf("%d\n",find(str));
			del(root);
		}
	}
	return 0;
}