Is Bitwise OR of Even Numbers in an Array easy or hard?

This problem is considered Easy because it relies on basic array traversal and a simple bitwise operation. The key idea is recognizing that you only process even numbers and accumulate the result using the OR operator in a single pass.

Bitwise OR of Even Numbers in an Array Python/Java solution

The implementation is identical across languages: iterate through the array, check if the value is even, and apply result |= value. Python, Java, C++, Go, and TypeScript all support the same bitwise OR operator, making the logic straightforward to port between languages.

How to solve Bitwise OR of Even Numbers in an Array in O(n)?

Iterate through the array and keep a variable called result initialized to 0. For each element, check if it is even using (num & 1) == 0. If it is even, update the accumulator with result |= num. After the traversal finishes, result contains the OR of all even numbers.

What is the best approach for Bitwise OR of Even Numbers in an Array?

The best approach is a single-pass simulation that scans the array once and maintains a running bitwise OR value. For every number, check if it is even using (num & 1) == 0 and merge it with result |= num. This runs in O(n) time with O(1) extra space.

Is Bitwise OR of Even Numbers in an Array asked at Google/Amazon/Meta?

Problems involving bitwise operations and array traversal frequently appear in interviews at companies like Google, Amazon, and Meta. While this exact question may vary, the pattern of filtering elements and aggregating with bitwise operators is common in coding interviews.

What data structure is used in Bitwise OR of Even Numbers in an Array?

The primary data structure is a simple array that stores the input integers. The optimal algorithm does not require additional structures beyond a single integer accumulator used to compute the running bitwise OR.

What is the time complexity of Bitwise OR of Even Numbers in an Array?

The optimal solution runs in O(n) time because each element in the array is visited exactly once. The algorithm performs a constant-time parity check and a bitwise OR operation per element. Space complexity is O(1) since only a single accumulator variable is maintained.

Description Hints 1 Solution Video 3:58

3688. Bitwise OR of Even Numbers in an Array

Easy84.9% acceptance2 companies

You are given an integer array nums.

Return the bitwise OR of all even numbers in the array.

If there are no even numbers in nums, return 0.

Example 1:

Input: nums = [1,2,3,4,5,6]

Output: 6

Explanation:

The even numbers are 2, 4, and 6. Their bitwise OR equals 6.

Example 2:

Input: nums = [7,9,11]

Output: 0

Explanation:

There are no even numbers, so the result is 0.

Example 3:

Input: nums = [1,8,16]

Output: 24

Explanation:

The even numbers are 8 and 16. Their bitwise OR equals 24.

Constraints:

1 <= nums.length <= 100
1 <= nums[i] <= 100

Asked at 2 companies

Microsoft Meta

Topics

Hints open one at a time

Hint 1

Simulate as described

3:58

Still stuck?Read the written solution, or watch a walkthrough.

Open solution

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1class Solution:
2    def evenNumberBitwiseORs(self, nums: List[int]) -> int:
3        

Starter codePython 3Spaces: 4

Examples

Case 1Case 2Case 3

Input

[1,2,3,4,5,6]

Input

[7,9,11]

Input

[1,8,16]

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