try the trie

#include <map>
#include <set>
#include <list>
#include <cmath>
#include <ctime>
#include <deque>
#include <queue>
#include <stack>
#include <string>
#include <bitset>
#include <cstdio>
#include <limits>
#include <vector>
#include <climits>
#include <cstring>
#include <cstdlib>
#include <fstream>
#include <numeric>
#include <sstream>
#include <iostream>
#include <algorithm>
#include <unordered_map>

using namespace std;
struct trieNode
{
    struct trieNode* children[26];
    bool isEndOfWord;    
};

struct trieNode *createNode()
{
    struct trieNode *node = new trieNode;
    
    for(int i = 0; i < 26; i++)
    {
        node->children[i] = NULL;
    }
    
    node->isEndOfWord = false;
    
    return node;
}

void addWord(string s, struct trieNode *root)
{
    struct trieNode* trv = root;
    int n = s.length(); 
    for(int i = 0; i < n; i++)
    {
        int index = s[i] - 'a';
        if(!trv->children[index])
            trv->children[index] = createNode();
        
        trv = trv->children[i];
    }
    
    trv->isEndOfWord = true;
}
    
    
int main(){
    int n;
    cin >> n;
    for(int a0 = 0; a0 < n; a0++){
        string op;
        string contact;
        cin >> op >> contact;
        
    }
    return 0;
}