LeetCode: Add Binary Solution

Approach

Plus each bit from right to left with remainder

Reverse the bit array so that we could do that from right to left

Implementation

1var addBinary = function (a, b) {
2  let length = Math.max(a.length, b.length)
3
4  a = a.padStart(length, "0").split("").map(Number).reverse()
5  b = b.padStart(length, "0").split("").map(Number).reverse()
6
7  let res = []
8  let remainder = 0
9
10  for (let i = 0; i < length || remainder; i++) {
11    let sum = (a[i] || 0) + (b[i] || 0) + remainder
12    res.push(sum % 2)
13    remainder = Math.floor(sum / 2)
14  }
15
16  return res.reverse().join("")
17}