hdu 2222 Keywords Search

来源：互联网发布：医疗软件销售编辑：程序博客网时间：2024/04/28 10:14

AC自动机模板题，刚学习这个东西，有的地方还不是很明白。

代码：

#include <queue>#include <cstdio>        #include <cstring>    #include <iostream>    #include <algorithm>using namespace std;const int SIZE = 26;const int MAX = 10000*50 + 10;struct Trie{int next[MAX][SIZE],end[MAX],fail[MAX];int root,L;int newnode(){//create a new nodefor(int i=0; i<26; i++)next[L][i] = -1;end[L++] = 0;return L - 1;}void init(){//initialise the trie treeL = 0;root = newnode();}void insert(char buf[]){//insert a string into the trie treeint now = root, len = strlen(buf);for(int i=0; i<len; i++){if(next[now][buf[i]-'a'] == -1)next[now][buf[i]-'a'] = newnode();now = next[now][buf[i]-'a'];}end[now]++;}void build(){//build the Aho-Corasickqueue <int> Q;for(int i=0; i<26; i++){if(next[root][i] == -1) next[root][i] = root;else{fail[next[root][i]] = root;Q.push(next[root][i]);}}while(!Q.empty()){int now = Q.front();Q.pop();for(int i=0; i<26; i++){if(next[now][i] == -1) next[now][i] = next[fail[now]][i];else{fail[next[now][i]] = next[fail[now]][i];Q.push(next[now][i]);}}}}int query(char buf[]){int len = strlen(buf), now = root;int res = 0;for(int i=0; i<len; i++){now = next[now][buf[i]-'a'];int temp = now;while(temp != root){res += end[temp];end[temp] = 0;temp = fail[temp];}}return res;}};Trie AC;char buf[1000010];int main(){int cas, num;scanf("%d",&cas);while(cas--){AC.init();scanf("%d",&num);for(int i=0; i<num; i++){scanf("%s",buf);AC.insert(buf);}AC.build();scanf("%s",buf);printf("%d\n",AC.query(buf));}return 0;}

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