hdu 2222 Keywords_ac自动机模板

题意：给你n个单词，再给你一串字符，求在字符中有多少个单词出现过

#include <iostream>
#include<cstdio>
#include<cstring>
using namespace std;
#define N 10010
#define MAXLEN 1000010
struct node{
	node *child[26];
	node *fail;
	int count;
	void init(){
		for(int i=0;i<26;i++)
			child[i]=NULL;
		count=0;
		fail=NULL;
	}
}*q[50*N];
node *root;
int head,tail;
void insert(char *str){//构建前缀树
	node *now,*next;
	int i=0,t;
	now=root;
	while(str[i]){
		t=str[i]-'a';
		if(now->child[t]!=NULL)
			now=now->child[t];
		else{
			next=new node;
			next->init();
			now->child[t]=next;
			now=next;
		}
		i++;
	}
	now->count++;
}
void build_fail(){
	int i;
	node *now,*p;
	head=tail=0;
	now=root;
	q[tail++]=now;
	while(head<tail){
		now=q[head];
		for(i=0;i<26;i++){
			if(now->child[i]==NULL) continue;
			if(now==root) now->child[i]->fail=root;
			else{
				p=now->fail;
				while(p!=NULL){
					if(p->child[i]!=NULL){
						now->child[i]->fail=p->child[i];
						break;
					}
					p=p->fail;
				}
				if(p==NULL) now->child[i]->fail=root;
			}
			q[tail++]=now->child[i];
		}
		head++;
	}
}
int query(char *str){
	node *now,*temp;
	int i,t,cnt;
	i=cnt=0;
	now=root;
	while(str[i]){
		t=str[i]-'a';
		while(now->child[t]==NULL&&now!=root) now=now->fail;
		now=now->child[t];
		if(now==NULL) now=root;
		temp=now;
		while(temp!=NULL&&temp->count!=-1){
			cnt+=temp->count;
			temp->count=-1;
			temp=temp->fail;
		}
		i++;
	}
	return cnt;
}
int main(int argc, char** argv) {
	int t,n;
	char str[MAXLEN];
	scanf("%d",&t);
	while(t--){
		scanf("%d",&n);
		root=new node;
		root->init();
		while(n--){
			scanf("%s",str);
			insert(str);
		}
		build_fail();
		scanf("%s",str);
		printf("%d\n",query(str));
	}
	return 0;
}