（难度Medium） Problem 106. Construct Binary Tree from Inorder and Postorder Traversal（中序和后序还原二叉树）

Construct Binary Tree from Inorder and Postorder Traversal

Medium

## Description

Given inorder and postorder traversal of a tree, construct the binary tree.

Note:
You may assume that duplicates do not exist in the tree.

For example, given

inorder = [9,3,15,20,7]
postorder = [9,15,7,20,3]

Return the following binary tree:

    3
/ \
9  20
/  \
15   7