前缀统计【字典树 Trie】

​​CH1601​​​、​​ACwing142​​

#include<bits/stdc++.h>
using namespace std;

#define
const int N = 1e6;

int n,m,num;
string s;

struct Node{
    int p;
    int son[26];
    int flag;
} tree[N + 5];

void build(){
    int now = 0;
    for(int i = 0;s[i];++i){
        if(tree[now].son[s[i] - 'a'] == 0)
            tree[now].son[s[i] - 'a'] = ++num;
        now = tree[now].son[s[i] - 'a'];
    }
    tree[now].flag += 1;
}

int find(){
    int ans = 0,now = 0;
    for(int i = 0;s[i];++i){
        if(tree[now].son[s[i] - 'a'])
            now = tree[now].son[s[i] - 'a'];
        else
            break;
        ans += tree[now].flag;
    }
    return ans;
}

signed main(){
    cin>>n>>m;
    for(int i = 1;i <= n;++i){
        cin>>s;
        build();
    }
    for(int i = 1;i <= m;++i){
        cin>>s;
        cout<<find()<<"\n";
    }
    return 0;
}