LeetCode in Kotlin
898. Bitwise ORs of Subarrays
Medium
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
Solution
class Solution {
fun subarrayBitwiseORs(arr: IntArray): Int {
val set: MutableSet<Int> = HashSet()
for (i in arr.indices) {
set.add(arr[i])
for (j in i - 1 downTo 0) {
if (arr[i] or arr[j] == arr[j]) {
break
}
arr[j] = arr[j] or arr[i]
set.add(arr[j])
}
}
return set.size
}
}