PlusOne.java

import java.util.Arrays;

public class PlusOne { 
 
 public int[] plusOne(int[] digits) {
 int n = digits.length;
 for (int i = n - 1; i >= 0; i--) {
 if (digits[i] < 9) {
 digits[i]++;
 return digits;
 }
 digits[i] = 0;
 }
 int[] newNumber = new int[n + 1];
 newNumber[0] = 1; 
 return newNumber;
 }

 public static void main(String[] args) {
 PlusOne solution = new PlusOne(); 

 int[] test1 = {1, 2, 3};
 System.out.println("Input: " + Arrays.toString(test1));
 System.out.println("Output: " + Arrays.toString(solution.plusOne(test1)));
 }
}