Leetcode - Valid Mountain Array

Given an array A of integers, return true if and only if it is a valid mountain array.

Recall that A is a mountain array if and only if:

• A.length >= 3
• There exists some i with 0 < i < A.length - 1 such that:
  • A[0] < A[1] < ... A[i-1] < A[i]
  • A[i] > A[i+1] > ... > A[A.length - 1]

Example 1:

Input: [2,1]
Output: false

Example 2:

Input: [3,5,5]
Output: false

Example 3:

Input: [0,3,2,1]
Output: true

Note:

1. 0 <= A.length <= 10000
2. 0 <= A[i] <= 10000 

Link : https://leetcode.com/problems/valid-mountain-array/

 Solution :

class Solution {
    public boolean validMountainArray(int[] A) {
        int i=0;
       
        while(i<A.length && i+1< A.length && A[i]< A[i+1]){
            i++;
        }
       
        if(i==0 || i+1>=A.length){
            return false;
        }
       
        while(i<A.length && i+1<A.length){
            if(A[i]<=A[i++ +1]){
                return false;
            }
       
        }
       
        return true;
       
    }
}