67. Add Binary

https://leetcode.com/problems/add-binary/

JavaScript

/**
 * @param {string} a
 * @param {string} b
 * @return {string}
 */
var addBinary = function(a, b) {
  a = a.split('').reverse()
  b = b.split('').reverse()

  var carry = 0
  var result = []
  var len = Math.max(a.length, b.length)

  for (let i = 0; i < len; i++) {
    let sum = (+a[i] || 0) + (+b[i] || 0) + carry
    result.push(sum % 2)
    carry = sum / 2 >> 0
  }

  if (carry) {
    result.push(carry)
  }

  return result.reverse().join('')
}

Python

class Solution(object):

    def addBinary(self, a, b):
        """
        :type a: str
        :type b: str
        :rtype: str
        """
        result = []
        carry = 0
        for i in range(max(len(a), len(b))):
            val1 = int(a[-i - 1]) if i < len(a) else 0
            val2 = int(b[-i - 1]) if i < len(b) else 0
            val = val1 + val2 + carry
            result.append(str(val % 2))
            carry = val // 2
        if carry > 0:
            result.append(str(carry))
        return ''.join(result[::-1])