You may recall that an array arr is a mountain array if and only if:
arr.length >= 3- There exists some index
i(0-indexed) with0 < i < arr.length - 1such that:arr[0] < arr[1] < ... < arr[i - 1] < arr[i]arr[i] > arr[i + 1] > ... > arr[arr.length - 1]
Given an integer array arr, return the length of the longest subarray, which is a mountain. Return 0 if there is no mountain subarray.
Example 1:
Input: arr = [2,1,4,7,3,2,5] Output: 5 Explanation: The largest mountain is [1,4,7,3,2] which has length 5.
Example 2:
Input: arr = [2,2,2] Output: 0 Explanation: There is no mountain.
Constraints:
1 <= arr.length <= 1040 <= arr[i] <= 104
Follow up:
- Can you solve it using only one pass?
- Can you solve it in
O(1)space?