67. Add Binary

Given two binary strings, return their sum (also a binary string).

The input strings are both non-empty and contains only characters 1 or 0.

Example 1:

Input: a = “11”, b = “1”
Output: “100”
Example 2:

Input: a = “1010”, b = “1011”
Output: “10101”

Constraints:

Each string consists only of ‘0’ or ‘1’ characters.
1 <= a.length, b.length <= 10^4
Each string is either “0” or doesn’t contain any leading zero.

解题思路：
bin()函数 – 返回一个整数 int 或者长整数 long int 的二进制表示。
返回的数值是以0b开头，表明返回的数值是二进制
int() 函数用于将一个字符串或数字转换为整型。
class int(x, base=10)
x – 字符串或数字。
base – 进制数，默认十进制。（指定base为非十进制时，x 需以字符串形式传入）

class Solution(object):
    def addBinary(self, a, b):
        """
        :type a: str
        :type b: str
        :rtype: str
        """
        print(bin(int(a,2)+int(b,2)))
        return bin(int(a,2)+int(b,2))[2:]