# LC 2401. Longest Nice Subarray

### [Problem link](https://leetcode.com/problems/longest-nice-subarray/)

###### tags: `leedcode` `medium` `c++` `Sliding Window`

You are given an array <code>nums</code> consisting of **positive** integers.

We call a subarray of <code>nums</code> **nice** if the bitwise **AND** of every pair of elements that are in **different** positions in the subarray is equal to <code>0</code>.

Return the length of the **longest** nice subarray.

A **subarray** is a **contiguous** part of an array.

**Note** that subarrays of length <code>1</code> are always considered nice.

**Example 1:**

Input: nums = [1,3,8,48,10]
Output: 3
Explanation: The longest nice subarray is [3,8,48]. This subarray satisfies the conditions:
- 3 AND 8 = 0.
- 3 AND 48 = 0.
- 8 AND 48 = 0.
It can be proven that no longer nice subarray can be obtained, so we return 3.

**Example 2:**

Input: nums = [3,1,5,11,13]
Output: 1
Explanation: The length of the longest nice subarray is 1. Any subarray of length 1 can be chosen.

**Constraints:**

- <code>1 <= nums.length <= 10⁵</code>
- <code>1 <= nums[i] <= 10⁹</code>

## Solution 1 - Sliding Window
#### C++

class Solution {
public:
    int longestNiceSubarray(vector<int>& nums) {
        int cnt = 0;
        int ans = 0;
        int l = 0;
        for (int r = 0; r < nums.size(); r++) {
            while ((nums[r] & cnt) > 0) {
                cnt ^= nums[l];
                l++;
            }
            cnt |= nums[r];
            ans = max(ans, r - l + 1);
        }
        return ans;
    }
};

>### Complexity
>| | Time Complexity | Space Complexity |
>| ----------- | --------------- | ---------------- |
>| Solution 1 | O(n) | O(1) |

## Note
x