[백준] 10814번 나이순 정렬

import java.util.ArrayList;
import java.util.Collections;
import java.util.Scanner;

public class Main {
	
	static class Infor implements Comparable<Infor>{
		
		int num;
		String name;
		int age;
		
		
		public Infor(int num, String name, int age) {
			this.num = num;
			this.name = name;
			this.age = age;
		}
		
		@Override
		public int compareTo(Infor o) {
			if(this.age == o.age) {
				return this.num - o.num;
			}
			return this.age - o.age;
		}
	}
	
	public static void main(String args[]) {
		
		Scanner kb = new Scanner(System.in);
		
		int n = kb.nextInt();
		ArrayList<Infor> list = new ArrayList<>();
		for(int i=0; i<n; i++) {
			int age = kb.nextInt();
			String name = kb.next();
			list.add(new Infor(i, name, age));
		}
		
		
		Collections.sort(list);
		
		for(int i=0; i<list.size(); i++) {
			System.out.println(list.get(i).age+ " "+ list.get(i).name);
		}


	}
}