2419. Longest Subarray with Maximum Bitwise And

Problem Statement

2419. Longest Subarray With Maximum Bitwise AND

Medium

You are given an integer array nums of size n.

Consider a non-empty subarray from nums that has the maximum possible bitwise AND.

In other words, let k be the maximum value of the bitwise AND of any subarray of nums. Then, only subarrays with a bitwise AND equal to k should be considered.

Return the length of the longest such subarray.

The bitwise AND of an array is the bitwise AND of all the numbers in it.

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

Example 1:

Input: nums = [1,2,3,3,2,2]
Output: 2
Explanation:
The maximum possible bitwise AND of a subarray is 3.
The longest subarray with that value is [3,3], so we return 2.

Example 2:

Input: nums = [1,2,3,4]
Output: 1
Explanation:
The maximum possible bitwise AND of a subarray is 4.
The longest subarray with that value is [4], so we return 1.

Constraints:

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

Java

Source file

class Solution {
    public int longestSubarray(int[] nums) {
        int max = 0, count = 0, maxcount = 0;
        for (int i = 0; i < nums.length; i++)
            max = Math.max(max, nums[i]);
        for (int i = 0; i < nums.length; i++) {
            if (max == nums[i])
                count++;
            else {
                maxcount = Math.max(maxcount, count);
                count = 0;
            }
        }
        maxcount = Math.max(maxcount, count);
        return maxcount == 0 ? 1 : maxcount;
    }
}