(LeetCode 3171):

Problem

You are given an array nums and an integer k. You need to find a subarray of nums such that the absolute difference between k and the bitwise OR of the subarray elements is as small as possible. In other words, select a subarray nums[l..r] such that |k - (nums[l] OR nums[l + 1] ... OR nums[r])| is minimum.

Return the minimum possible value of the absolute difference.

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

 

Example 1:

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

Output: 0

Explanation:

The subarray nums[0..1] has OR value 3, which gives the minimum absolute difference |3 - 3| = 0.

Example 2:

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

Output: 1

Explanation:

The subarray nums[1..1] has OR value 3, which gives the minimum absolute difference |3 - 2| = 1.

Example 3:

Input: nums = [1], k = 10

Output: 9

Explanation:

There is a single subarray with OR value 1, which gives the minimum absolute difference |10 - 1| = 9.

 

Constraints:

  • 1 <= nums.length <= 105
  • 1 <= nums[i] <= 109
  • 1 <= k <= 109