Construct Binary Tree from Preorder and Postorder Traversal

arrayhash tabledivide and conquer

Problem Statement

Given two integer arrays, preorder and postorder where preorder is the preorder traversal of a binary tree of distinct values and postorder is the postorder traversal of the same tree, reconstruct and return the binary tree .

If there exist multiple answers, you can return any of them.

Examples

Example 1

Input: preorder = [1,2,4,5,3,6,7], postorder = [4,5,2,6,7,3,1]
Output: [1,2,3,4,5,6,7]

Example 2

Input: preorder = [1], postorder = [1]
Output: [1]

Constraints

1 <= preorder.length <= 30

1 <= preorder[i] <= preorder.length

All the values of preorder are unique .

postorder.length == preorder.length

1 <= postorder[i] <= postorder.length

All the values of postorder are unique .

It is guaranteed that preorder and postorder are the preorder traversal and postorder traversal of the same binary tree.

🤔

Medium

Difficulty

Topic Info

ModuleDSA

CategoryArray

Sub-topicHash Table