- Difficulty: Medium
- Tags: LeetCode, Medium, Tree, Array, Hash Table, Divide and Conquer, Binary Tree, leetcode-106, Recursion, O(n), LintCode, EPI
Problem
Given two integer arrays inorder
and postorder
where inorder
is the inorder traversal of a binary tree and postorder
is the postorder traversal of the same tree, construct and return the binary tree.
Example 1:
Input: inorder = [9,3,15,20,7], postorder = [9,15,7,20,3] Output: [3,9,20,null,null,15,7]
Example 2:
Input: inorder = [-1], postorder = [-1] Output: [-1]
Constraints:
1 <= inorder.length <= 3000
postorder.length == inorder.length
-3000 <= inorder[i], postorder[i] <= 3000
inorder
andpostorder
consist of unique values.- Each value of
postorder
also appears ininorder
. inorder
is guaranteed to be the inorder traversal of the tree.postorder
is guaranteed to be the postorder traversal of the tree.