[프로그래머스/C++] 전화번호 목록

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

코딩테스트 연습 - 전화번호 목록

 

내 풀이 (정답)

#include <string>
#include <vector>
#include <algorithm>

using namespace std;

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

 

다른 풀이 (해시이용) - 문제에서 원한 답 같다

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

using namespace std;

bool solution(vector<string> phone_book) {
    bool answer = true;

    unordered_map<string, int> hash_map;
    for(int i = 0; i < phone_book.size(); i++)
        hash_map[phone_book[i]] = 1;

    for(int i = 0; i < phone_book.size(); i++) {
        string phone_number = "";
        for(int j = 0; j < phone_book[i].size(); j++) {
            phone_number += phone_book[i][j];
            if(hash_map[phone_number] && phone_number != phone_book[i])
                answer = false;
        }
    }

    return answer;
}

 

처음 풀이  (오답)

#include <string>
#include <vector>

using namespace std;

bool solution(vector<string> phone_book) {
    bool answer = true;
    string front = phone_book[0];
    int num = front.size();
    
    for(int i=1; i<phone_book.size(); i++){
        if(phone_book[i].substr(0,num) == front){
            return false;
        }
    }
    
    return answer;
}