LeetCode: Plus One Solution

1/**
2 * @param {number[]} digits
3 * @return {number[]}
4 */
5var plusOne = function (digits) {
6  let mem = 0
7  digits = digits.reverse().map((digit, i) => {
8    digit += mem + (i === 0 ? 1 : 0)
9    if (digit > 9) {
10      mem = 1
11      digit = 0
12    } else {
13      mem = 0
14    }
15    return digit
16  })
17  if (mem === 1) {
18    digits.push(1)
19  }
20  return digits.reverse()
21}