■Map을 Key값이 아닌 Value를 이용하여 정렬

결론적으로는 불가능함

Map의 정렬은 Key값을 기준으로 정렬이 가능하고

Value들을 활용하여 정렬하려면 따로 빼줘서 정렬해줘야 한다..

 

참고 : https://codechacha.com/ko/java-sort-map/

 

 

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
 
 
public class Main {
        
    private static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    private static BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
    
    static class Point{
        int idx;
        int total;
        public Point(int idx, int total) {
            this.idx = idx;
            this.total = total;
        }
        
    }
    
    public static void main(String[] args) throws IOException{
        Map<String, Point> map = new HashMap<>();
        map.put("Nepal", new Point(1,100));
        map.put("United States", new Point(2,400));
        map.put("India", new Point(3,50));
        map.put("England", new Point(4,1000));
        map.put("Australia", new Point(5,300));
 
        List<Point> valueList = new ArrayList<>(map.values());
        valueList.sort((p1,p2)-> p2.total-p1.total);
        for (Point point : valueList) {
            System.out.println(point.total+" "+point.idx);
        }
        
        bw.write("");
        bw.flush();
        bw.close();
    }
    
//    private static int stoi(String input) {
//        return Integer.parseInt(input);
//    }
}

output:

1000 4
400 2
300 5
100 1
50 3