36: Add one
Given an array of integers. The array represents a non-negative integer, add one to this number
Note: the most significant digit is the first item of the array
Example 1
Input: [1, 2, 3, 4]
Output: [1, 2, 3, 5]
Explanation:
[1, 2, 3, 4]=1234,1234+1=1235
Example 2
Input: [1, 9]
Output: [2, 0]