67-Add-Binary.md

67. Add Binary

Given two binary strings a and b, return their sum as a binary string.

Example 1:

Input: a = "11", b = "1"
Output: "100"

Example 2:

Input: a = "1010", b = "1011"
Output: "10101"

Constraints:

• 1 <= a.length, b.length <= 104
• a and b consist only of '0' or '1' characters.
• Each string does not contain leading zeros except for the zero itself.

Solution

class Solution:
    def addBinary(self, a: str, b: str) -> str:
        ans = ""
        a, b = list(a), list(b)
        carry = 0
        while a or b or carry:
            if a:
                carry += int(a.pop())
            if b:
                carry += int(b.pop())
            ans = str(carry & 1) + ans
            carry >>= 1
        return ans

Simple binary addition.