[백준 10814] 나이순 정렬 (Java)

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.IOException;
import java.util.StringTokenizer;
import java.util.Arrays;
import java.util.Comparator;
 
public class Main{
    public static void main(String[] args) throws IOException{
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        
        int n = Integer.parseInt(br.readLine());
        People[] ppl = new People[n];
 
        StringTokenizer st;
        for(int i=0; i<n; i++){
            st = new StringTokenizer(br.readLine());
            int age = Integer.parseInt(st.nextToken());
            String name = st.nextToken();
 
            ppl[i] = new People(age, name);
        }
 
        Arrays.sort(ppl, new Comparator<People>(){
            @Override
            public int compare(People p1, People p2){
                return p1.age - p2.age;
            }
        });
 
        StringBuilder sb = new StringBuilder();
 
        for(int i=0; i<n; i++){
            sb.append(ppl[i].age).append(" ").append(ppl[i].name).append("\n");
        }
 
        System.out.print(sb);
    }
 
    public static class People{
        int age; String name;
 
        public People(int age, String name){
            this.age = age;
            this.name = name;
        }
    }
}