67. 二进制求和 @Python@Go

原题

https://leetcode.cn/problems/add-binary/description/

思路

模拟, 从右向左遍历

复杂度

时间：O(n)
空间：O(n)

Python代码

class Solution:
    def addBinary(self, a: str, b: str) -> str:
        ans = ''
        i = len(a) - 1
        j = len(b) - 1 
        carry = 0 
        while i >= 0 or j >= 0 or carry > 0:
            if i >= 0:
                carry += int(a[i])
                i -= 1 
            if j >= 0:
                carry += int(b[j])
                j -= 1 
            digit = carry % 2 
            carry //= 2
            ans = str(digit) + ans 
        return ans

Go代码

func addBinary(a string, b string) string {
	var ans string
	i, j := len(a)-1, len(b)-1
	carry := 0
	for i >= 0 || j >= 0 || carry > 0 {
		if i >= 0 {
			carry += int(a[i] - '0')
			i--
		}
		if j >= 0 {
			carry += int(b[j] - '0')
			j--
		}
		digit := carry % 2
		carry /= 2
		ans = string('0'+digit) + ans
	}
	return ans
}