Envío 6216

Código

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        String largeNumber = scanner.nextLine();
        int numberToAdd = scanner.nextInt();
        char[] numberArray = largeNumber.toCharArray();

        for(int i=numberArray.length-1; i>=0; i--){
            int number = convertCharToInt(numberArray[i]);
            int sum = number + numberToAdd;
            if(sum >= 10){
                int newNumber = sum - 10;
                numberToAdd = 1;
                numberArray[i] = convertIntToChar(newNumber);
            } else {
                numberArray[i] =  convertIntToChar(sum);
                numberToAdd = 0;
                break;
            }
        }

        if(numberToAdd == 1){
            System.out.print(1);
        }
        for(int i=0; i<numberArray.length; i++){
            System.out.print(numberArray[i]);
        }
    }

    private static int convertCharToInt(char c){
        switch (c){
            case '0': return 0;
            case '1': return 1;
            case '2': return 2;
            case '3': return 3;
            case '4': return 4;
            case '5': return 5;
            case '6': return 6;
            case '7': return 7;
            case '8': return 8;
            case '9': return 9;
            default:
                System.out.println("NOT GOOD"); return -1;
        }
    }

    private static char convertIntToChar(int x){
        switch (x){
            case 0: return '0';
            case 1: return '1';
            case 2: return '2';
            case 3: return '3';
            case 4: return '4';
            case 5: return '5';
            case 6: return '6';
            case 7: return '7';
            case 8: return '8';
            case 9: return '9';
            default:
                System.out.println("NOT GOOD"); return 'n';
        }
    }
}