Leetcode 算法题 67
题名：Add Binary
https://leetcode.com/problems/add-binary/#/description

题目描述：给定两个二进制字符串，返回他们的和（二进制字符串）

Given two binary strings, return their sum (also a binary string).
For example,
a = “11”
b = “1”
Return “100”.

解题思路：这道题的解答方法有很多，我的思路是把二进制字符串转化为十进制的整数，然后相加，再把结果转化为二进制的字符串

Python代码如下

class Solution(object):
    def addBinary(self, a, b):
        """
        :type a: str
        :type b: str
        :rtype: str
        """

        dec_a = str2dec(a)
        dec_b = str2dec(b)
        dec_c = dec_a + dec_b

        return dec2binStr(dec_c)


def str2dec(s):
    sum = 0
    for i in s:
        sum = sum * 2 + int(i)
    return sum


def dec2binStr(s):
    ls = []
    while s:
        rem = s % 2
        s = s / 2
        ls.insert(0, str(rem))
    if len(ls) != 0:
        return ''.join(ls)
    else:
        return "0"