Algorithm
Problem Name: 898. Bitwise ORs of Subarrays
Problem Link: https://leetcode.com/problems/bitwise-ors-of-subarrays/
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.
Constraints:
1 <= arr.length <= 5 * 1040 <= arr[i] <= 109
Code Examples
#1 Code Example with Javascript Programming
Code -
Javascript Programming
const subarrayBitwiseORs = function(A) {
let cur = new Set()
const ans = new Set()
for (let i = 0; i < A.length; i++) {
const item = A[i]
const x = new Set()
for (let e of cur.values()) {
x.add(e | item)
}
x.add(item)
cur = x
for (let sub of cur.values()) {
ans.add(sub)
}
}
return ans.size
};
Input
arr = [0]
Output
1
#2 Code Example with Python Programming
Code -
Python Programming
class Solution:
def subarrayBitwiseORs(self, A):
nums, n, pre = set(), len(A), set()
for a in A:
pre = {a} | {num | a for num in pre}
nums |= pre
return len(nums)
Input
arr = [0]
Output
1