Given a non-empty array of digits representing a non-negative integer, increment one to the integer.

PlusOne.cs

public class Solution {
    public int[] PlusOne(int[] digits) {
        
        int len = digits.Length;
        
        if(len == 0){
            return digits;
        }
        
        int i=len-1;
        int carry = 1;
        while(i>=0){
            if(digits[i]+carry>9){
                int pcarry = (digits[i]+carry)/10;
                digits[i] = (digits[i]+carry)%10;
                carry = pcarry;
            }
            else{
                digits[i] = digits[i]+carry;
                carry = 0;
            }

            if(carry == 0){
                break;
            }
            i--;
            
        }
        
        if(carry>0){
            
            int[] tDigits = new int[len+1];
            tDigits[0] = carry;
            for(i=0;i<len;i++){
                tDigits[i+1] = digits[i];
            }
            digits = tDigits;
        }
        
        return digits;
        
    }
}