Watch 10 video solutions for Valid Mountain Array, a easy level problem involving Array. This walkthrough by Kevin Naughton Jr. has 26,226 views views. Want to try solving it yourself? Practice on FleetCode or read the detailed text solution.
Given an array of integers arr, return true if and only if it is a valid mountain array.
Recall that arr is a mountain array if and only if:
arr.length >= 3i with 0 < i < arr.length - 1 such that:
arr[0] < arr[1] < ... < arr[i - 1] < arr[i] arr[i] > arr[i + 1] > ... > arr[arr.length - 1]
Example 1:
Input: arr = [2,1] Output: false
Example 2:
Input: arr = [3,5,5] Output: false
Example 3:
Input: arr = [0,3,2,1] Output: true
Constraints:
1 <= arr.length <= 1040 <= arr[i] <= 104