백준,1931,회의실배정

Problem1931.java

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Arrays;
import java.util.Comparator;

public class Problem1931 {

	static int size;
	
	public static void main(String[] args) throws NumberFormatException, IOException {
		
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		size = Integer.parseInt(br.readLine());
		int[][] meetings  = new int[size][2];
		
		// 데이터 입력 
		for(int i = 0; i < size; i++) {
			String[] datas = br.readLine().split(" ");
			
			meetings[i][0] = Integer.parseInt(datas[0]);
			meetings[i][1] = Integer.parseInt(datas[1]);
		}
		
		// 종료 시간으로 정렬 
		Arrays.sort(meetings, new Comparator<int[]>() {

			@Override
			public int compare(int[] a, int[] b) {
				
				if(a[1] < b[1]) {
					return -1;
				} else if(a[1] == b[1]) {
					return a[0] <= b[0] ? -1 : 1;
				} 
				
				return 1;
			}
			
		});
		
		int count = 1;
		int[] prev = meetings[0];
		for(int i = 1; i < size; i++) {
			
			if(prev[1] <= meetings[i][0]) {
				count++;
				prev = meetings[i];
			}
		}
		
		System.out.println(count);
	}
}

Problem1931.py

import sys
read = sys.stdin.readline

N = int(read())
meetings = []

i = 0
while i < N:
    datas = read().split()
    meetings.append((int(datas[0]), int(datas[1])))
    i += 1
    
meetings = sorted(meetings, key=(lambda x: (x[1], x[0])))

prev_meeting = meetings[0]
count = 1

for idx, meeting in enumerate(meetings):
    if idx == 0:
        continue
    
    if prev_meeting[1] <= meeting[0]:
        prev_meeting = meeting
        count += 1

print(count)