Introduction

In this blog post, we will explore how to solve the LeetCode problem "2419" 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

You are given an integer array nums of size n. Consider a non-empty subarray from nums that has the maximum possible bitwise AND. In other words, let k be the maximum value of the bitwise AND of any subarray of nums. Then, only subarrays with a bitwise AND equal to k should be considered. Return the length of the longest such subarray. The bitwise AND of an array is the bitwise AND of all the numbers in it. A subarray is a contiguous sequence of elements within an array. Example 1: Input: nums = [1,2,3,3,2,2] Output: 2 Explanation: The maximum possible bitwise AND of a subarray is 3. The longest subarray with that value is [3,3], so we return 2. Example 2: Input: nums = [1,2,3,4] Output: 1 Explanation: The maximum possible bitwise AND of a subarray is 4. The longest subarray with that value is [4], so we return 1. Constraints: 1 <= nums.length <= 105 1 <= nums[i] <= 106

Explanation

Here's the breakdown of the approach and the Python code:

• Find the Maximum AND: Iterate through the array to find the maximum possible bitwise AND value that can be achieved by any subarray.
• Identify Qualifying Subarrays: Iterate through the array again, this time identifying subarrays whose bitwise AND equals the maximum AND found in the previous step.

• Determine Longest Length: Keep track of the length of the longest qualifying subarray encountered.

• Runtime Complexity: O(n), where n is the length of the input array. Storage Complexity: O(1).

Code

    def longest_subarray_with_max_bitwise_and(nums):
    """
    Finds the length of the longest subarray with the maximum possible bitwise AND.

    Args:
        nums: An integer array.

    Returns:
        The length of the longest subarray with the maximum bitwise AND.
    """

    max_and = 0
    for num in nums:
        max_and = max(max_and, num)

    max_len = 0
    curr_len = 0
    for num in nums:
        if num == max_and:
            curr_len += 1
            max_len = max(max_len, curr_len)
        else:
            curr_len = 0

    return max_len