Introduction

In this blog post, we will explore how to solve the LeetCode problem "67" using AI. LeetCode is a popular platform for preparing for coding interviews, and with the help of AI tools like Chatmagic, we can generate solutions quickly and efficiently - helping you pass the interviews and get the job offer without having to study for months.

Problem Statement

Given two binary strings a and b, return their sum as a binary string. Example 1: Input: a = "11", b = "1" Output: "100" Example 2: Input: a = "1010", b = "1011" Output: "10101" Constraints: 1 <= a.length, b.length <= 104 a and b consist only of '0' or '1' characters. Each string does not contain leading zeros except for the zero itself.

Explanation

Here's a breakdown of the solution and the Python code:

• High-Level Approach:

  • Iterate through the binary strings from right to left, similar to how we perform manual addition.
  • Maintain a carry variable to handle overflow when the sum of bits at a particular position exceeds 1.
  • Append the resulting bit (0 or 1) to the beginning of the result string.

• Complexity:

  • Runtime Complexity: O(max(len(a), len(b)))
  • Storage Complexity: O(max(len(a), len(b))) - due to the result string

Code

    def addBinary(a: str, b: str) -> str:
    """
    Given two binary strings a and b, return their sum as a binary string.

    Example 1:
    Input: a = "11", b = "1"
    Output: "100"

    Example 2:
    Input: a = "1010", b = "1011"
    Output: "10101"

    Constraints:
    1 <= a.length, b.length <= 104
    a and b consist only of '0' or '1' characters.
    Each string does not contain leading zeros except for the zero itself.
    """

    result = ""
    i = len(a) - 1
    j = len(b) - 1
    carry = 0

    while i >= 0 or j >= 0 or carry:
        sum_bits = carry

        if i >= 0:
            sum_bits += int(a[i])
            i -= 1

        if j >= 0:
            sum_bits += int(b[j])
            j -= 1

        result = str(sum_bits % 2) + result
        carry = sum_bits // 2

    return result