Add Binary

問題描述：

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

For example,
a = “11”
b = “1”
Return “100”.

參考答案（python）：

class Solution(object):
    def addBinary(self, a, b):
        if len(a)==0: return b
        if len(b)==0: return a
        if a[-1] == '1' and b[-1] == '1'
 
:
            return self.addBinary(self.addBinary(a[0:-1],b[0:-1]),'1')+'0'
        if a[-1] == '0' and b[-1] == '0':
            return self.addBinary(a[0:-1],b[0:-1])+'0'
        else:
            return self.addBinary(a[0:-1],b[0:-1])+'1'        

效能：

參考答案（python）：

class Solution(object):
    def addBinary
 
(self, a, b):
        a = int(a, 2)
        b = int(b, 2)
        return bin(a+b)[2:]

效能：

參考答案（c++）：

class Solution
{
public:
    string addBinary(string a, string b)
    {
        string s = "";

        int c = 0, i = a.size() - 1, j = b.size() - 1;
        while(i >= 0 || j >= 0 || c == 1
 
)
        {
            c += i >= 0 ? a[i --] - '0' : 0;
            c += j >= 0 ? b[j --] - '0' : 0;
            s = char(c % 2 + '0') + s;
            c /= 2;
        }

        return s;
    }
};

效能：