978. Longest Turbulent Subarray

A subarray A[i], A[i+1], ..., A[j] of A is said to be turbulent if and only if:

For i <= k < j, A[k] > A[k+1] when k is odd, and A[k] < A[k+1] when k is even;
OR, for i <= k < j, A[k] > A[k+1] when k is even, and A[k] < A[k+1] when k is odd.

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

Return the length of a maximum size turbulent subarray of A.

Example 1:

Input: [9,4,2,10,7,8,8,1,9]
Output: 5
Explanation: (A[1] > A[2] < A[3] > A[4] < A[5])

Example 2:

Input: [4,8,12,16]
Output: 2

Example 3:

Input: [100]
Output: 1

Note:

---

	class Solution {
	public int maxTurbulenceSize(int[] A) {
	int inc = 1, dec = 1, ans = 1;

	for (int i = 1; i < A.length; i++) {
	if (A[i] < A[i - 1]) {
	dec = inc + 1;
	inc = 1;
	} else if (A[i] > A[i - 1]) {
	inc = dec + 1;
	dec = 1;
	} else {
	inc = 1;
	dec = 1;
	}

	ans = Math.max(ans, Math.max(inc, dec));
	}

	return ans;
	}
	}

SWE Interview preparation