Check If Preorder Traversal Is Valid

Determine whether a given array ARR of positive integers is a valid Preorder Traversal of a Binary Search Tree (BST).

A binary search tree (BST) is a tree structure where each node's value is greater than all values in its left subtree and less than all values in its right subtree.

Input:

The first line contains an integer, 'T', representing the number of test cases.
The first line of each test case consists of an integer 'N', indicating the number of elements in the array 'ARR'.
The second line contains 'N' space-separated integers representing the elements of the array 'ARR'.

Output:

For each test case, output 1 if the array is a valid preorder traversal of a BST; otherwise, output 0.
Each result should be on a new line.

Example:

Input:
2
3
7 4 8
3
1 5 3

Output:

1
0

Explanation:

For the first test case, the sequence 7 4 8 can represent a BST, while for the second test case, the sequence 1 5 3 cannot.

Constraints:

• 1 ≤ T ≤ 10
• 1 ≤ N ≤ 105
• 0 ≤ ARR[i] ≤ 109

Note: You do not need to print anything. Just implement the function as described.