baekjoon 7785 회사에 있는 사람 ] 자료구조 Map (Treemap / 사전 역순 정렬 Collections.reverseOrder())

import java.util.Collections;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Scanner;
import java.util.StringTokenizer;
import java.util.TreeMap;

public class Main {
    public static void main(String[] args){

        Map<String,String> googleEntry = new TreeMap<>(Collections.reverseOrder());

        Scanner sc = new Scanner(System.in);
        int testCase = sc.nextInt();
        String what = sc.nextLine();
        String[] tokenStr = new String[2];

        for(int i = 0; i < testCase; i++) {
            String bundle = sc.nextLine();
            StringTokenizer st = new StringTokenizer(bundle);
            tokenStr[0] = st.nextToken();
            tokenStr[1] = st.nextToken();
            if(tokenStr[1].equals("enter"))googleEntry.put(tokenStr[0], tokenStr[1]);
            else googleEntry.remove(tokenStr[0]);
        }

        for(Entry<String, String> test : googleEntry.entrySet()) {
            System.out.println(test.getKey());
        }

    }
}