How do you solve Longest Subarray With Maximum Bitwise AND on LeetCode?

Longest Subarray With Maximum Bitwise AND (LeetCode #2419) can be solved using Brute Force or Optimal Solution. The optimal approach is Optimal Solution with O(n) time complexity and O(1) space complexity. Key insight: The maximum bitwise AND of a subarray can only be achieved by using elements that are equal to the maximum element in the array.

What is the time complexity of Longest Subarray With Maximum Bitwise AND?

The optimal solution for Longest Subarray With Maximum Bitwise AND runs in O(n) time and uses O(1) space. This complexity is achieved because we only traverse the array twice: once to find the maximum and once to count the longest contiguous segment.

What is the brute force solution for Longest Subarray With Maximum Bitwise AND?

The brute force approach for Longest Subarray With Maximum Bitwise AND is Brute Force, with O(n²) time complexity and O(1) space complexity. The brute force approach checks every possible subarray to find the maximum bitwise AND and its longest occurrence. This is straightforward but inefficient for larger arrays. The optimal Optimal Solution approach improves this to O(n).

What algorithm or data structure is used to solve Longest Subarray With Maximum Bitwise AND?

Longest Subarray With Maximum Bitwise AND uses the following concepts: Array, Bit Manipulation, Brainteaser. The recommended patterns to study are: Hash Map, Array.

What are the interview tips for Longest Subarray With Maximum Bitwise AND?

Always consider edge cases, such as arrays with all identical elements or arrays with a single element. Clarify the definition of the problem to ensure you understand what a subarray is. Think about the properties of bitwise operations and how they relate to the maximum values in the array.

What are common mistakes when solving Longest Subarray With Maximum Bitwise AND?

Failing to recognize that only the maximum value contributes to the maximum bitwise AND. Not handling the case of multiple contiguous maximum values correctly.

#2419

Longest Subarray With Maximum Bitwise AND

Medium

ArrayBit ManipulationBrainteaserHash MapArray

LeetCode ↗

Approaches

Brute ForceOptimal

Complexity Comparison

	Brute Force	Optimal Solution★
Time	O(n²)	O(n)
Space	O(1)	O(1)

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Intuition

Time O(n)Space O(1)

The optimal solution leverages the fact that the maximum bitwise AND can only be formed by contiguous elements that are equal to the maximum value in the array. Thus, we can simply find the maximum number and count its longest contiguous occurrence.

⚙️

Algorithm

2 steps

1Step 1: Find the maximum value in the array.
2Step 2: Iterate through the array to count the length of the longest contiguous subarray of this maximum value.

solution.py14 lines

1def longest_subarray_with_max_bitwise_and(nums):
2    max_value = max(nums)
3    max_length = 0
4    current_length = 0
5    for num in nums:
6        if num == max_value:
7            current_length += 1
8            max_length = max(max_length, current_length)
9        else:
10            current_length = 0
11    return max_length
12
13# Example usage
14print(longest_subarray_with_max_bitwise_and([1, 2, 3, 3, 2, 2]))

ℹ

Complexity note: This complexity is achieved because we only traverse the array twice: once to find the maximum and once to count the longest contiguous segment.

1The maximum bitwise AND of a subarray can only be achieved by using elements that are equal to the maximum element in the array.
2Contiguous segments of the maximum value determine the length of the longest subarray.

Solutions and explanations are original Tejav content. Problem titles © LeetCode — use the LeetCode button above for the full problem statement.