Class Solution


  • public class Solution
    extends Object
    941 - Valid Mountain Array.

    Easy

    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 >= 3
    • There exists some i 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 <= 104
    • 0 <= arr[i] <= 104
    • Constructor Detail

      • Solution

        public Solution()
    • Method Detail

      • validMountainArray

        public boolean validMountainArray​(int[] arr)