백준 1431번 시리얼 번호 [ Java ]

1431번: 시리얼 번호

java8의 스트림을 이용하여 풀었습니다.

import java.io.*;
import java.util.*;

public class Main {
    public static void main(String[] args) throws IOException{
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringBuilder sb = new StringBuilder();
        int N = Integer.parseInt(br.readLine());
        String[] serial = new String[N];
        while (N-->0) serial[N] = br.readLine();
        Arrays.stream(serial).sorted(new Comparator<String>() {
            @Override
            public int compare(String o1, String o2) {
                if (o1.length()==o2.length()){
                    int fst = Arrays.stream(o1.split(""))
                            .filter(str->str.matches("^[0-9]+$"))
                            .mapToInt(Integer::parseInt)
                            .sum();
                    int sec = Arrays.stream(o2.split(""))
                            .filter(str->str.matches("^[0-9]+$"))
                            .mapToInt(Integer::parseInt)
                            .sum();
                    if (fst==sec) return o1.compareTo(o2);
                    return fst-sec;
                }
                return o1.length()-o2.length();
            }
        }).forEach(str->sb.append(str+"\n"));
        System.out.print(sb);
    }
}