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

lc67

class Solution:
    def addBinary(self, a: str, b: str) -> str:
        res = []
        len_a = len(a)
        len_b = len(b)
        i = 0
        carry = 0
        while i < len_a or i < len_b:
            sum = carry
            if i < len_a:
                sum += int(a[len_a-1-i])
            if i < len_b:
                sum += int(b[len_b-1-i])
            remainder = int(sum % 2)
            res.append(str(remainder))
            carry = floor(sum / 2)
            i += 1
        if carry:
            res.append("1")
        return ''.join(res[::-1])