Count Number of Maximum Bitwise-OR Subsets

IF
AlgoAxiomStaff Engineers
JSTS
Medium20 mins

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 that have this 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

Example 1:

Input: nums = [3,1]

Output: 2

Explanation: The maximum possible bitwise OR of a subset is 3. The subsets with OR equal to 3 are [3] and [3,1], so the answer is 2.

Example 2:

Input: nums = [2,2,2]

Output: 7

Explanation: The maximum possible bitwise OR is 2. Every non-empty subset has OR = 2. There are 2^3 - 1 = 7 non-empty subsets.

Example 3:

Input: nums = [3,2,1,5]

Output: 6

Explanation: The maximum possible bitwise OR of a subset is 7. There are 6 subsets with bitwise OR of 7.

Constraints

  • 1 <= nums.length <= 16
  • 1 <= nums[i] <= 10^5
Source: Subsets pattern — AlgoAxiom
JavaScript
Test Case 1
root = [1, 2, 3]
Test Case 2
root = [1, 2, 3, 4, 5]
Idle