P2580 于是他错误的点名开始了(Trie)

 https://www.luogu.com.cn/problem/P2580

#include <bits/stdc++.h>
using namespace std;
const int maxn = 5e5 + 5;
int n,m;
string s;
int num;
struct node{
    int son[27],cnt;
    bool flag;
}trie[maxn];
void insert(string s){
    int u = 0;
    for(int i = 0; i < s.size(); i++){
        int v = s[i] - 'a';
        if(!trie[u].son[v])
            trie[u].son[v] = ++num;
        u = trie[u].son[v];
    }
    trie[u].flag = true;
}
int find(string s){
    int u = 0;
    for(int i = 0; i < s.size(); i++){
        int v = s[i] - 'a';
        if(!trie[u].son[v]) return 3;
        u = trie[u].son[v];
    }
    if(!trie[u].flag)
        return 3;
    if(!trie[u].cnt){
        trie[u].cnt++;
        return 1;
    }
    return 2;
}
int main(){
    //freopen("in","r",stdin);
    ios::sync_with_stdio(0);
    cin >> n;
    for(int i = 0; i < n; i++){
        cin >> s;
        insert(s);
    }
    cin >> m;
    for(int i = 0; i < m; i++) {
        cin >> s;
        if(find(s) == 1)
            cout << "OK
";
        else if(find(s) == 2)
            cout << "REPEAT
";
        else cout << "WRONG
";
    }

    return 0;
}

UVA11362 Phone List

https://www.luogu.com.cn/problem/UVA11362

#include<bits/stdc++.h>

using namespace std;
const int maxn = 4e5 + 5;

struct node {
    int son[11], sum;
    bool flag;

    void clear() {
        memset(son, 0, sizeof(son));
        sum = 0;
        flag = 0;
    }
} trie[maxn];

int n, t, num;
string s[maxn];

void insert(string s) {
    int len = s.size(), u = 0;
    for (int i = 0; i < len; i++) {
        int v = s[i] - '0';
        if (!trie[u].son[v])
            trie[u].son[v] = ++num;
        trie[u].sum++;
        u = trie[u].son[v];
    }
    trie[u].flag = true;
}

int find(string s) {
    int len = s.size(), u = 0;
    for (int i = 0; i < len; i++) {
        int v = s[i] - '0';
        if (!trie[u].son[v]) return 0;
        u = trie[u].son[v];
    }
    if (trie[u].sum == 0)return 0;
    return 1;
}

int main() {
    //freopen("in", "r", stdin);
    cin >> t;
    while (t--) {
        num = 0;
        for (int i = 0; i < maxn; i++)
            trie[i].clear();
        cin >> n;
        for (int i = 0; i < n; i++) {
            cin >> s[i];
            insert(s[i]);
        }
        bool ans = false;
        for (int i = 0; i < n; i++) {
            int res = find(s[i]);
            if (res == 1) {
                ans = true;
                break;
            }
        }
        if (ans) cout << "NO
";
        else cout << "YES
";
    }
}

大佬的博客

https://www.luogu.com.cn/blog/juruohyfhaha/trie-xue-xi-zong-jie