[프로그래머스 문제풀이68]오픈채팅방 js

function solution(record) {
    var answer = [];
    const users={}
    for(let i=record.length-1;i>=0;i--){
        const recordSplit=record[i].split(" ");
        const id=recordSplit[1];
        const nick=recordSplit[2];
        if(users[id]===undefined){
            users[id]=nick;
        }
       
    }
    for(let i=0;i<record.length;i++){
        const recordSplit=record[i].split(" ");
        const act=recordSplit[0];
        const id=recordSplit[1];
        if(act==="Enter"){
            answer.push(`${users[id]}님이 들어왔습니다.`)
        }
        if(act==="Leave"){
            answer.push(`${users[id]}님이 나갔습니다.`)
        }
    }
    
    
    return answer;
}