Leetcode•Jul 10, 2026

Bitwise ORs of Subarrays

Hazrat Ali

Leetcode

Given an integer array arr, return the number of distinct bitwise ORs of all the non-empty subarrays of arr.

The bitwise OR of a subarray is the bitwise OR of each integer in the subarray. The bitwise OR of a subarray of one integer is that integer.

A subarray is a contiguous non-empty sequence of elements within an array.

 

Example 1:

Input: arr = [0]
Output: 1
Explanation: There is only one possible result: 0.

Example 2:

Input: arr = [1,1,2]
Output: 3
Explanation: The possible subarrays are [1], [1], [2], [1, 1], [1, 2], [1, 1, 2].
These yield the results 1, 1, 2, 1, 3, 3.
There are 3 unique values, so the answer is 3.

Example 3:

Input: arr = [1,2,4]
Output: 6
Explanation: The possible results are 1, 2, 3, 4, 6, and 7.

Solution
/**
 * @param {number[]} arr
 * @return {number}
 */
var subarrayBitwiseORs = function(arr) {
    let result = new Set();
    let prev = new Set();

    for (let num of arr) {
        let curr = new Set();
        curr.add(num);

        for (let val of prev) {
            curr.add(val | num);
        }

        for (let val of curr) {
            result.add(val);
        }

        prev = curr;
    }

    return result.size;
};



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