PlusOne.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace LeetCodeSolutions.LeetCodeProblems
{
    /*
     You are given a large integer represented as an integer array digits, where each digits[i] is the ith digit of the integer.
     The digits are ordered from most significant to least significant in left-to-right order.
     The large integer does not contain any leading 0's.
    
    Increment the large integer by one and return the resulting array of digits.

    Example 1:
    
    Input: digits = [1,2,3]
    Output: [1,2,4]
    Explanation: The array represents the integer 123.
    Incrementing by one gives 123 + 1 = 124.
    Thus, the result should be [1,2,4].   
     */


    public class PlusOne
    {
        public int[] PlusOneSolution(int[] digits)
        {

            int l = digits.Length;
            for (int i = l - 1; i >= 0; i--)
            {
                if (digits[i] < 9)
                {
                    digits[i]++;
                    return digits;
                }
                digits[i] = 0;
            }                    

            int[] result = new int[l + 1];
            result[0] = 1; 
            return result;
        }
    }
}