[JAVA] 백준 11650번 - 좌표 정렬하기

https://www.acmicpc.net/problem/11650

11650번: 좌표 정렬하기

 

import java.awt.*;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.Collections;
import java.util.StringTokenizer;

class Point implements Comparable<Point> {
    public int x, y;

    public Point(int x, int y) {
        this.x = x;
        this.y = y;
    }

    @Override
    public int compareTo(Point p) {
        if (this.x == p.x) return this.y - p.y;
        else return this.x - p.x;
    }
}

public class Main{
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringTokenizer st;
        int n = Integer.parseInt(br.readLine());

        ArrayList<Point> arr = new ArrayList<Point>();
        for(int i=0; i<n; i++){
            st = new StringTokenizer(br.readLine());
            int x = Integer.parseInt(st.nextToken());
            int y = Integer.parseInt(st.nextToken());
            arr.add(new Point(x, y));
        }
        Collections.sort(arr);
        for (Point p : arr) {
            System.out.println(p.x+" "+p.y);
        }
    }
}

 

 

Comparable 인터페이스를 구현해 정렬 기준을 제공하고, Collections.sort로 그 기준에 따라 좌표를 정렬한다.