67. Add Binary

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

For example,
a = "11"
b = "1"
Return "100".

 

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

bin():将整数x转换为二进制字符串,前面会带'0b';

int(a,2),a是二进制，将其转换为十进制。

 

class Solution:
    def addBinary(self, a, b):
        return bin(eval('0b' + a) + eval('0b' + b))[2:]

eval()可以将字符串当成表达式来求值