- Difficulty: Medium
- Tags: LeetCode, Medium, Tree, Array, Hash Table, Divide and Conquer, Binary Tree, leetcode-105, Recursion, O(n), LintCode, EPI
Problem
Given two integer arrays preorder
and inorder
where preorder
is the preorder traversal of a binary tree and inorder
is the inorder traversal of the same tree, construct and return the binary tree.
Example 1:
Input: preorder = [3,9,20,15,7], inorder = [9,3,15,20,7] Output: [3,9,20,null,null,15,7]
Example 2:
Input: preorder = [-1], inorder = [-1] Output: [-1]
Constraints:
1 <= preorder.length <= 3000
inorder.length == preorder.length
-3000 <= preorder[i], inorder[i] <= 3000
preorder
andinorder
consist of unique values.- Each value of
inorder
also appears inpreorder
. preorder
is guaranteed to be the preorder traversal of the tree.inorder
is guaranteed to be the inorder traversal of the tree.