baekjoon 11650

key : lamda 표현식

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.IOException;
import java.util.*;

class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringBuilder sb = new StringBuilder();
        int N = Integer.parseInt(br.readLine());
        StringTokenizer coordinate;
        int[][] coordinateArray= new int[N][2];
        int x, y;
        for (int n = 0; n < N; n++){
            coordinate = new StringTokenizer(br.readLine());
            x = Integer.parseInt(coordinate.nextToken());
            y = Integer.parseInt(coordinate.nextToken());
            coordinateArray[n][0] = x;
            coordinateArray[n][1] = y;
        }
        Arrays.sort(coordinateArray, (eX1, eX2) -> {
            if(eX1[0]==eX2[0])
                return eX1[1] - eX2[1];
            else
                return eX1[0] - eX2[0];
        });
        for (int n = 0; n < N; n++)
            sb.append(coordinateArray[n][0] + " " + coordinateArray[n][1]).append('\n');
        System.out.print(sb);
        br.close();
    }
}