LeetCode 2044, Medium. Topics: Array, Backtracking, Bit Manipulation, Enumeration. View on LeetCode.
Generate this problem as a practice environment: tested reference solution, 20 parametrized pytest cases, and a playground notebook:
Problem
Given an integer array nums, find the maximum possible bitwise OR of a subset of nums and return the number of different non-empty subsets with the maximum bitwise OR.
An array a is a subset of an array b if a can be obtained from b by deleting some (possibly zero) elements of b. Two subsets are considered different if the indices of the elements chosen are different.
The bitwise OR of an array a is equal to a[0] OR a[1] OR ... OR a[a.length - 1] (0-indexed).
Examples
Explanation: The maximum possible bitwise OR of a subset is 3. There are 2 subsets with a bitwise OR of 3:
Explanation: All non-empty subsets of [2,2,2] have a bitwise OR of 2. There are 2^3 - 1 = 7 total subsets.
Explanation: The maximum possible bitwise OR of a subset is 7. There are 6 subsets with a bitwise OR of 7:
[3,5]
[3,1,5]
[3,2,5]
[3,2,1,5]
[2,5]
[2,1,5]
Constraints
1 <= nums.length <= 16
1 <= nums[i] <= 10^5
Solution
Reference implementation from solution.py on GitHub, full suite in test_solution.py:
Complexity
NeetCode All. Last modified on September 7, 2026