Given preorder and inordertraversal of a tree, construct the binary tree.
给定一个二叉树的前序和中序遍历，重建这棵二叉树。
2
Given preorder and inordertraversal of a tree, construct the binary tree.
给定先序和中序遍历，构造二叉树。
3
In the data structure, the binary tree can be uniquely confirmed when the nodes sequences of this binary tree for preorder traversal and inordertraversal are knows.