Sort By Digits Sum - JAVA

// Author : Saurav Kalsoor
// Sort By Digit Sum - JAVA

import java.util.*;

public class Test {

    static Scanner sc = new Scanner(System.in);
    public static void main(String[] args) {
        int n = sc.nextInt();
        ArrayList<Integer> arr = new ArrayList<>();

        for(int i=0; i < n; i++) {
            int input = sc.nextInt();
            arr.add(input);
        }

        ArrayList<Integer> result = sortByDigits(arr);

        for(int i=0; i < n; i++)
            System.out.print(result.get(i) + " ");

        System.out.println();
    }

    public static ArrayList<Integer> sortByDigits(ArrayList<Integer> arr){
        Collections.sort(arr, new SortBySumOfDigits());
        return arr;
    }
}

class SortBySumOfDigits implements Comparator<Integer> {

    public int compare(Integer a, Integer b){

        int sumA = getSum(a), sumB = getSum(b);
        if(sumA == sumB){
            return a - b;
        }
        else{
            return sumA - sumB;
        }
    }

    public int getSum(int n){
        int sum = 0;
        while(n > 0){
            sum = sum + n%10;
            n = n/10;
        }
        return sum;
    }
}