【LeetCode with Python】 Add Binary

博客域名：http://www.xnerv.wang
原题页面：https://oj.leetcode.com/problems/add-binary/
题目类型：模拟运算
难度评价：★
本文地址：http://blog.csdn.net/nerv3x3/article/details/4137815

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

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

用字符串模拟二进制整数加法。写了一个更通用的算法，修改self.radix即可将代码改为如八进制整数加法、十进制整数加法等。

class Solution:    def __init__(self):        self.radix = 2    # @param a, a string    # @param b, a string    # @return a string    def addBinary(self, a, b):        a_nums = [(ord(ch) - ord('0')) for ch in a]        b_nums = [(ord(ch) - ord('0')) for ch in b]        a_nums_size = len(a_nums)        b_nums_size = len(b_nums)        max_nums_size = max(a_nums_size, b_nums_size)        a_extend_nums = [0 for i in range(0, max_nums_size - a_nums_size)]        b_extend_nums = [0 for i in range(0, max_nums_size - b_nums_size)]        a_nums = a_extend_nums + a_nums        b_nums = b_extend_nums + b_nums        sum_nums = [0] * max_nums_size        carry = 0        for i in range(max_nums_size - 1, -1, -1):            sum = a_nums[i] + b_nums[i] + carry            sum_nums[i] = sum % self.radix            carry = sum / self.radix        sum_str = ("1" if 1 == carry else "")        for i in range(0, max_nums_size):            sum_str += chr(sum_nums[i] + ord('0'))        return sum_str