boj - 11650 좌표정렬하기(자바)

package boj;

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.Arrays;
import java.util.Comparator;
import java.util.List;

import java.util.stream.Collectors;

public class boj_11650 {
    public static void main(String[] args) throws IOException {
        BufferedReader r = new BufferedReader(new InputStreamReader(System.in));
        BufferedWriter w = new BufferedWriter(new OutputStreamWriter(System.out));
        int count = Integer.parseInt(r.readLine());

        List<List<Integer>> points = new ArrayList<>();

        put(r, count, points);
        List<List<Integer>> collect = sorted(points);
        print(w, collect);

        w.flush();
    }

    private static void put(BufferedReader r, int count, List<List<Integer>> points) throws IOException {
        for (int i = 0; i < count; i++) {
            List<Integer> point = Arrays.stream(r.readLine().split(" "))
                    .map(Integer::parseInt)
                    .collect(Collectors.toList());
            points.add(point);
        }
    }

    private static List<List<Integer>> sorted(List<List<Integer>> points) {
        List<List<Integer>> collect = points.stream()
                .sorted(Comparator.comparingInt((List<Integer> point) -> point.get(0))
                        .thenComparingInt(point -> point.get(1))).collect(Collectors.toList());
        return collect;
    }

    private static void print(BufferedWriter w, List<List<Integer>> collect) throws IOException {
        for (List<Integer> i : collect) {
            w.write(i.get(0) + " " + i.get(1));
            w.newLine();
        }
    }


}