Leetcode-Plus One

 1 public class Solution {
 2     public int[] plusOne(int[] digits) {
 3         int carry = 1;
 4         int index = digits.length-1;
 5         while (carry==1 && index>=0){
 6             int val = digits[index]+carry;
 7             carry = val/10;
 8             val = val%10;
 9             digits[index]=val;
10             index--;
11         }
12         int[] res;
13         if (index<0 && carry==1){
14            res = new int[digits.length+1];
15            res[0]=carry;
16            for (int i=0;i<digits.length;i++)
17                res[i+1] = digits[i];
18         } else res = digits;
19         return res;
20     }
21 }