Watch 10 video solutions for Construct Binary Search Tree from Preorder Traversal, a medium level problem involving Array, Stack, Tree. This walkthrough by NeetCode has 307,238 views views. Want to try solving it yourself? Practice on FleetCode or read the detailed text solution.
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.
Example 1:
Input: preorder = [8,5,1,7,10,12] Output: [8,5,10,1,7,null,12]
Example 2:
Input: preorder = [1,3] Output: [1,null,3]
Constraints:
1 <= preorder.length <= 1001 <= preorder[i] <= 1000preorder are unique.