67. Add Binary

🟩 Easy

Solution

My Solution

func addBinary(a string, b string) string {
    if len(a) < len(b) {
        a, b = b, a
    }
    bin := make([]byte, len(a)+1)
    var (
        carry byte
        a_num byte
        b_num byte
    )
    for i, j := len(a), len(b); i >= 1 || j >= 1; {
        i, j = i-1, j-1

        if i >= 0 {
            a_num = a[i] - '0'
        } else {
            a_num = 0
        }
        if j >= 0 {
            b_num = b[j] - '0'
        } else {
            b_num = 0
        }
        num := a_num ^ b_num ^ carry
        carry = a_num & b_num | carry & (a_num ^ b_num)
        bin[i+1] = num + '0'
    }
    if carry == 1 {
        bin[0] = '1'
        return string(bin)
    }
    return string(bin[1:])
}

result

Leetcode: link