Introduction

In this blog post, we will explore how to solve the LeetCode problem "1073" 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 numbers arr1 and arr2 in base -2, return the result of adding them together. Each number is given in array format: as an array of 0s and 1s, from most significant bit to least significant bit. For example, arr = [1,1,0,1] represents the number (-2)^3 + (-2)^2 + (-2)^0 = -3. A number arr in array, format is also guaranteed to have no leading zeros: either arr == [0] or arr[0] == 1. Return the result of adding arr1 and arr2 in the same format: as an array of 0s and 1s with no leading zeros. Example 1: Input: arr1 = [1,1,1,1,1], arr2 = [1,0,1] Output: [1,0,0,0,0] Explanation: arr1 represents 11, arr2 represents 5, the output represents 16. Example 2: Input: arr1 = [0], arr2 = [0] Output: [0] Example 3: Input: arr1 = [0], arr2 = [1] Output: [1] Constraints: 1 <= arr1.length, arr2.length <= 1000 arr1[i] and arr2[i] are 0 or 1 arr1 and arr2 have no leading zeros

Explanation

Here's a breakdown of the approach, followed by the Python code:

• Simulate Base -2 Addition: Perform addition digit by digit, similar to adding in base 10, but taking into account that we are in base -2. This involves handling carries, which can be either positive or negative.

• Carry Handling: The crucial part is managing carries in base -2. If the sum of digits at a position is 2, we set the current digit to 0 and carry -1 to the next position. If the sum is 3, the current digit is 1 and we carry -1. If the sum is -1, we set current digit to 1 and carry 1 to the next.

• Remove Leading Zeros: After the addition is complete, remove any leading zeros from the result, except if the result is just [0].

• Time & Space Complexity: O(N), where N is the maximum length of the two input arrays. O(N) space for storing the result.

Code

    def addNegabinary(arr1, arr2):
    """
    Adds two numbers in base -2 represented as arrays of 0s and 1s.

    Args:
        arr1: The first number as an array of 0s and 1s.
        arr2: The second number as an array of 0s and 1s.

    Returns:
        The sum of the two numbers as an array of 0s and 1s.
    """

    i = len(arr1) - 1
    j = len(arr2) - 1
    carry = 0
    result = []

    while i >= 0 or j >= 0 or carry != 0:
        digit1 = arr1[i] if i >= 0 else 0
        digit2 = arr2[j] if j >= 0 else 0

        sum_digits = digit1 + digit2 + carry

        if sum_digits == 2:
            result.append(0)
            carry = -1
        elif sum_digits == 3:
            result.append(1)
            carry = -1
        elif sum_digits == -1:
            result.append(1)
            carry = 1
        else:
            result.append(sum_digits)
            carry = 0

        i -= 1
        j -= 1

    # Remove leading zeros
    while len(result) > 1 and result[-1] == 0:
        result.pop()

    return result[::-1]