Plus One

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