[프로그래머스 2] 오픈채팅방 (C/C++) (★)

#include <iostream>
#include <string>
#include <vector>
#include <map>
using namespace std;
 
vector<string> solution(vector<string> record) 
{
    vector<string> answer;
    vector<pair<string, string>> temp;
    map<string, string> reserve;
    
    for(int i = 0; i < record.size(); i++)
    {
        if(record[i][0] == 'E')
        {
            int j;
            string id;
            for(j = 6; record[i][j] != ' '; j++)
            {
                id += record[i][j];
            }
            
            string nickname;
            for(int k = j+1; k < record[i].size(); k++)
            {
                nickname += record[i][k];
            }
            
            reserve[id] = nickname;
            temp.push_back({id, "E"});
        }
        else if(record[i][0] == 'L')
        {
            int j;
            string id;
            for(j = 6; j < record[i].size(); j++)
            {
                id += record[i][j];
            }
            
            temp.push_back({id, "L"});
        }
        else if(record[i][0] == 'C')
        {
            int j;
            string id;
            for(j = 7; record[i][j] != ' '; j++)
            {
                id += record[i][j];
            }
            
            string nickname;
            for(int k = j+1; k < record[i].size(); k++)
            {
                nickname += record[i][k];
            }
            
            reserve[id] = nickname;
        }
    }
    
    for(int i = 0; i < temp.size(); i++)
    {
        string result;
        result += reserve[temp[i].first];
        
        if(temp[i].second == "E")
        {
            result += "님이 들어왔습니다.";   
        }
        else if(temp[i].second == "L")
        {
            result += "님이 나갔습니다.";   
        }
        
        answer.push_back(result);
    }
    
    return answer;
}