unordered_map or map

#include <iostream>
#include <cstring>
#include <map>
#include <unordered_map>
using namespace std;
// map<string, int> mp;
unordered_map<string, int> mp;
int main(){
    int n;
    cin >> n;
    char op;
    string s;
    while(n -- ){
        cin >> op >> s;
        if(op == 'Q'){
            cout << mp[s] << endl;
        }else   mp[s] += 1; 
    }
    return 0;
}

Trie

#include <iostream>
using namespace std;
const int N = 100010;
int str[N][30], cnt[2*10010], id;
int insert(char s[]){
    int p = 0;
    for(int i = 0; s[i]; i ++ ){
        int u = s[i] - 'a';
        if(!str[p][u])  str[p][u] = ++ id;
        p = str[p][u];
    }
    cnt[p] ++ ;
}
int query(char s[]){
    int p = 0;
    for(int i = 0; s[i]; i ++ ){
        int u = s[i] - 'a';
        if(!str[p][u])   return 0;
        p = str[p][u];
    }
    return cnt[p];
}
int main(){
    int n;
    cin >> n;
    char op;
    char s[N];
    while(n -- ){
        cin >> op >> s;
        if(op == 'Q')   cout << query(s) << endl;
        else    insert(s);
    }
    return 0;
}