## Algorithm

Problem Name: 978. Longest Turbulent Subarray

Given an integer array `arr`, return the length of a maximum size turbulent subarray of `arr`.

A subarray is turbulent if the comparison sign flips between each adjacent pair of elements in the subarray.

More formally, a subarray `[arr[i], arr[i + 1], ..., arr[j]]` of `arr` is said to be turbulent if and only if:

• For `i <= k < j`:
• `arr[k] > arr[k + 1]` when `k` is odd, and
• `arr[k] < arr[k + 1]` when `k` is even.
• Or, for `i <= k < j`:
• `arr[k] > arr[k + 1]` when `k` is even, and
• `arr[k] < arr[k + 1]` when `k` is odd.

Example 1:

```Input: arr = [9,4,2,10,7,8,8,1,9]
Output: 5
Explanation: arr[1] > arr[2] < arr[3] > arr[4] < arr[5]
```

Example 2:

```Input: arr = [4,8,12,16]
Output: 2
```

Example 3:

```Input: arr = [100]
Output: 1
```

Constraints:

• `1 <= arr.length <= 4 * 104`
• `0 <= arr[i] <= 109`

## Code Examples

### #1 Code Example with Javascript Programming

```Code - Javascript Programming```

``````
const maxTurbulenceSize = function(arr) {
const n = arr.length

return Math.max(helper(), helper1())
// < > <
function helper() {
const cnt = Array(n).fill(1)

for(let i = 0; i  <  n - 1; i++) {
if(i % 2 === 1 && arr[i] > arr[i + 1]) {
cnt[i + 1] = cnt[i] + 1
} else if(i % 2 === 0 && arr[i] < arr[i + 1]) {
cnt[i + 1] = cnt[i] + 1
}
}

return Math.max(...cnt)
}

function helper1() {
const cnt = Array(n).fill(1)

for(let i = 0; i  <  n - 1; i++) {
if(i % 2 === 1 &&  arr[i] < arr[i + 1] > {
cnt[i + 1] = cnt[i] + 1
} else if(i % 2 === 0 && arr[i] > arr[i + 1] ) {
cnt[i + 1] = cnt[i] + 1
}
}

return Math.max(...cnt)
}
};
``````
Copy The Code &

Input

cmd
arr = [9,4,2,10,7,8,8,1,9]

Output

cmd
5

### #2 Code Example with Python Programming

```Code - Python Programming```

``````
class Solution:
def maxTurbulenceSize(self, A):
arr = [A[i - 1] < A[i] for i in range(1, len(A))]
cur = mx = 1 + (len(A) > 1)
for i in range(1, len(arr)):
if A[i] != A[i + 1] and arr[i] != arr[i - 1]:
cur += 1
mx = max(cur, mx)
else:
cur = 2
return mx
``````
Copy The Code &

Input

cmd
arr = [9,4,2,10,7,8,8,1,9]

Output

cmd
5
Advertisements