敏感词过滤 AC自动机

复杂度n^2 ，没想出来怎么优化，‘*’赋值可以差分写，不过不减复杂度

#include <queue>
#include <cstdlib>
#include <cmath>
#include <cstdio>
#include <string>
#include <cstring>
#include <iostream>
#include <algorithm>
using namespace std;
typedef long long ll;
const int maxn =  2*1e3+9;
typedef pair<int,int> pii;

int trie[maxn][26]; 
int cntword[maxn];  
int fail[maxn];     
int cnt = 0;
int len[maxn];

void insertWords(string s){
    int root = 0;
    for(int i=0;i<(int)s.size();i++){
        int next = s[i] - 'a';
        if(!trie[root][next])
            {
                trie[root][next] = ++cnt;
                len[cnt]=len[root]+1;
            }
        root = trie[root][next];
    }
    cntword[root]++;      
}

void getFail(){
    queue <int>q;
    for(int i=0;i<26;i++){     
        if(trie[0][i]){
            fail[trie[0][i]] = 0;
            q.push(trie[0][i]);
        }
    }
    while(!q.empty()){
        int now = q.front();
        q.pop();

        for(int i=0;i<26;i++){  
            if(trie[now][i]){
                fail[trie[now][i]] = trie[fail[now]][i];
                q.push(trie[now][i]);
            }
            else
            trie[now][i] = trie[fail[now]][i];
        }
    }
}

std::vector<pii> v;
void query(string &s){
    int now = 0;
    for(int i=0;i<(int)s.size();i++){    
        now = trie[now][s[i]-'a']; 
        for(int j=now;j;j=fail[j]){
          
            if(cntword[j])
            {
                for(int ss=i-len[j]+1;ss<=i;ss++)
            {       
                    s[ss]='*';
            }
           // v.push({i-len[j]+1,i});
            break;
            }
        }
    }
    /*int p[maxn];
    int vis[maxn];
    memset(p,0,sizeof(p));
    memset(vis,0,sizeof(vis));
    for(pii x:v)
    {
        int 
    }    */
    
}


int main() {
    int n;
    string s;
    cin >> n;
    for(int i=0;i<n;i++){
        cin >> s ;
        insertWords(s);
    }
    fail[0] = 0;
    getFail();
    cin >> s ;
    query(s);
    cout<<s<<endl;
    //cout << query(s) << endl;
    return 0;
}