g1001_1100.s1008_construct_binary_search_tree_from_preorder_traversal

Class Solution

java.lang.Object

g1001_1100.s1008_construct_binary_search_tree_from_preorder_traversal.Solution

public class Solution
extends Object

1008 - Construct Binary Search Tree from Preorder Traversal.

Medium

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 <= 100
• 1 <= preorder[i] <= 1000
• All the values of preorder are unique.

Constructor Summary

Constructors

Constructor and Description
Solution()

Method Summary

Modifier and Type	Method and Description
TreeNode	bstFromPreorder(int[] preorder)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Solution

public Solution()

Method Detail

bstFromPreorder

public TreeNode bstFromPreorder(int[] preorder)