hdu2222-AC自动机板子

Aho板子
hdu2222
题意：t组数据，有n1e4个长度50的字符串，给了一个长度1e6模式串问模式串中有几个子串
代码：

#include <bits/stdc++.h>
using namespace std;
#define ll long long 
#define forn(i,n) for(int i=0;i<n;i++)
#define for1(i,n) for(int i=1;i<=n;i++)
#define IO ios::sync_with_stdio(false);cin.tie(0);cout.tie(0)
const int maxn = 5e5+5;
int trie[maxn][26],id,cnt[maxn],fail[maxn];
queue<int>q;
class Aho{
    public:
    void init(){
        memset(trie,0,sizeof(trie));
        memset(cnt,0,sizeof(cnt));
        memset(fail,0,sizeof(fail));
        id = 0;
    }
    void insert(string s){
        int len = s.size(),u = 0;
        forn(i,len){
            int x = s[i]-'a';
            if(!trie[u][x]) trie[u][x] = ++id;
            u = trie[u][x];
        }
        cnt[u]++;
    }
    void build(){
        forn(i,26) if(trie[0][i]) q.push(trie[0][i]);
        while(!q.empty()){
            int u = q.front();q.pop();
            forn(i,26){
                if(trie[u][i]) fail[trie[u][i]] = trie[fail[u]][i],q.push(trie[u][i]);
                else trie[u][i] = trie[fail[u]][i];
            }
        }
    }
    int find(string s){
        int len = s.size(),u = 0,res = 0;
        forn(i,len){
            int x = s[i]-'a';
            u = trie[u][x];
            for(int j = u;j&&cnt[j]!=-1;j = fail[j]){
                res+=cnt[j],cnt[j] = -1;
            }
        }
        return res;
    }
}aho;

int main(){
    IO;
    int t;cin>>t;
    while(t--){
        aho.init();
        int n;cin>>n;
        string s;forn(i,n){
            cin>>s;
            aho.insert(s);
        }
        aho.build();
        cin>>s;
        cout <<aho.find(s)<<'
'; 
    }
    return 0;
}