Package g2501_2600.s2588_count_the_number_of_beautiful_subarrays

Class Solution

  • public class Solution
extends Object
    2588 - Count the Number of Beautiful Subarrays.

    Medium

    You are given a 0-indexed integer array nums. In one operation, you can:

    • Choose two different indices i and j such that 0 <= i, j < nums.length.
    • Choose a non-negative integer k such that the kth bit ( 0-indexed ) in the binary representation of nums[i] and nums[j] is 1.
    • Subtract 2k from nums[i] and nums[j].

    A subarray is beautiful if it is possible to make all of its elements equal to 0 after applying the above operation any number of times.

    Return the number of beautiful subarrays in the array nums.

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

    Example 1:

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

    Output: 2

    Explanation: There are 2 beautiful subarrays in nums: [4,3,1,2,4] and [4,3,1,2,4].

    • We can make all elements in the subarray [3,1,2] equal to 0 in the following way:
      • Choose [3, 1, 2] and k = 1. Subtract 21 from both numbers. The subarray becomes [1, 1, 0].
      • Choose [1, 1, 0] and k = 0. Subtract 20 from both numbers. The subarray becomes [0, 0, 0].
    • We can make all elements in the subarray [4,3,1,2,4] equal to 0 in the following way:
      • Choose [4, 3, 1, 2, 4] and k = 2. Subtract 22 from both numbers. The subarray becomes [0, 3, 1, 2, 0].
      • Choose [0, 3, 1, 2, 0] and k = 0. Subtract 20 from both numbers. The subarray becomes [0, 2, 0, 2, 0].
      • Choose [0, 2, 0, 2, 0] and k = 1. Subtract 21 from both numbers. The subarray becomes [0, 0, 0, 0, 0].

    Example 2:

    Input: nums = [1,10,4]

    Output: 0

    Explanation: There are no beautiful subarrays in nums.

    Constraints:

    • 1 <= nums.length <= 105
    • 0 <= nums[i] <= 106

    • Constructor Detail

      • Solution

        public Solution()

    • Method Detail

      • beautifulSubarrays

        public long beautifulSubarrays​(int[] nums)