백준 1931 회의실 배정

https://www.acmicpc.net/problem/1931

package test;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.util.Arrays;
import java.util.Comparator;
import java.util.StringTokenizer;

public class BaekJoonQ1931_P207_Q31 {

	public static void main(String[] args) throws NumberFormatException, IOException {
		BufferedReader br =new BufferedReader(new InputStreamReader(System.in));
		BufferedWriter bw =new BufferedWriter(new OutputStreamWriter(System.out));
		StringTokenizer st;
		
		int meeting =Integer.parseInt(br.readLine());
		int meetingArr[][] = new int[meeting][2];
				
		for(int i=0;i<meeting;i++) {
			st =new StringTokenizer(br.readLine());
			meetingArr[i][0] =Integer.parseInt(st.nextToken());
			meetingArr[i][1] =Integer.parseInt(st.nextToken());
		}
		
		Arrays.sort(meetingArr,new Comparator<int[]>(){
			@Override
			public int compare(int[] o1, int[] o2) {
				if(o1[1] == o2[1]) {
					return o1[0] - o2[0];
				}
				
				return o1[1] - o2[1];
			}
		});
		
		int rooms=0;
		int endTime=0;
		
		for(int i=0;i<meeting;i++) {
			if(endTime<=meetingArr[i][0]) {
				endTime=meetingArr[i][1];
				++rooms;
			}
		}
		bw.write(rooms+"");
		bw.flush();
	}

}