LeetCode-in-Java

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

Solution

public class Solution {
    public int longestSubarray(int[] nums) {
        int maxVal = 0;
        int res = 0;
        int i = 0;
        while (i < nums.length) {
            int n = nums[i];
            if (n < maxVal) {
                i++;
                continue;
            }
            if (n > maxVal) {
                maxVal = n;
                res = 0;
            }
            int j = i + 1;
            while (j < nums.length && nums[j] == n) {
                j++;
            }
            res = Math.max(res, j - i);
            i = j - 1;
            i++;
        }
        return res;
    }
}

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