🐣 문제

링크 : https://school.programmers.co.kr/learn/courses/30/lessons/42577

🐥 코드

#include <string>
#include <vector>
#include <unordered_map>

using namespace std;

bool solution(vector<string> phone_book) {
    
    unordered_map<string, int> hash;
    
    for(int i = 0; i < phone_book.size(); i++){
        hash[phone_book[i]] = 1;
    }
    
    for (int i = 0; i < phone_book.size(); i++){
        for (int j = 0; j < phone_book[i].size() - 1; j++){
            string phone_number = phone_book[i].substr(0, j + 1);
            if (hash[phone_number]) return false;
        }
    }   
    return true;
}