Question

LeetCode #66

Given a non-negative integer represented as a non-empty array of digits, plus one to the integer.

You may assume the integer do not contain any leading zero, except the number 0 itself.

The digits are stored such that the most significant digit is at the head of the list.

What the question really means

Input Output
[2, 3, 5] [2, 3, 6]
[9, 9] [1, 0, 0]
[0] [1]

Pseudo code

  1. Loop through the given array from tail
  2. If the current digit is less than 9, add 1 and return
  3. If the current digit is 9, set it to 0
  4. Add [1] to the head of the array and return

Playground

See the Pen 66. Plus One by Cherry Wang (@chryw) on CodePen.