프로그래머스 오픈채팅방 - java

HashMap을 써보자. import java.util.*; class Solution { public String[] solution(String[] record) { String[] answer = {}; HashMap mapUidNickname = new HashMap(); ArrayList listResult = new ArrayList(); for (String log : record) { StringTokenizer st = new StringTokenizer(log); String operation = st.nextToken(); String uid = st.nextToken(); if (st.hasMoreTokens()) { String nickname = st.nextToken(); mapUidNickname.put(uid, nickname); } } for (String log : record) { StringTok...