Given an array of integers preorder, which represents the preorder traversal of a BST (i.e., binary search tree ), construct the tree and return its root .
It is guaranteed that there is always possible to find a binary search tree with the given requirements for the given test cases.
A binary search tree is a binary tree where for every node, any descendant of Node.left has a value strictly less than Node.val , and any descendant of Node.right has a value strictly greater than Node.val .
A preorder traversal of a binary tree displays the value of the node first, then traverses Node.left , then traverses Node.right .
1 <= preorder.length <= 1001 <= preorder[i] <= 1000All the values of preorder are unique .