classSolution{public:TreeNode*bstFromPreorder(vector<int>& preorder){if(preorder.empty())returnnullptr; TreeNode *node =newTreeNode(preorder[0]);inti =0, n = preorder.size();for(i =1; i < n; ++i) {if(preorder[i] > preorder[0])break; }vector<int>left(preorder.begin() +1...
1.因为二叉搜索树的特性,将preorder数组排序,得到inorder。再将inorder的元素和下标用map存储起来,再对其进行递归。 2.利用二叉树的特性,初始化最小值,最大值,进行递归 3.用栈结构进行迭代。 classSolution {int[] preorder;intidx = 0; Map<Integer, Integer> map_inorder =newHashMap<>();publicTreeNode...
(Recall that a binary search tree is a binary tree where for everynode, any descendant ofnode.lefthas a value<node.val, and any descendant ofnode.righthas a value>node.val. Also recall that a preorder traversal displays the value of thenodefirst, then traversesnode.left, then traversesn...
889. Construct Binary Tree from Preorder and Postorder Traversal,程序员大本营,技术文章内容聚合第一站。
* 1008. Construct Binary Search Tree from Preorder Traversal * https://leetcode.com/problems/construct-binary-search-tree-from-preorder-traversal/description/ * * Return the root node of a binary search tree that matches the given preorder traversal. (Recall that a binary search tree is a ...
105. Construct Binary Tree from Preorder and Inorder Traversal 题目描述: Given preorder and inorder traversal of a tree, construct the binary tree. Example 1: null Note: You may assume that duplicates do not exist in the tree. 题目翻译 给定一个树的前序和中序遍历,构造二叉树。 示例1: ...
Given inorder and postorder traversal of a tree, construct the binary tree. Note: You may assume that duplicates do not exist in the tree. 思路: easy 算法: 1. public TreeNode buildTree(int[] inorder, int[] postorder) { 2. if (inorder == null || inorder.length == 0 || postorde...
思路跟之间拿到inorder + preorder construct binary tree基本是一样的思路。根据postorder里最后面的是root的规律,我们维持一个postIndex从后面往前依次遍历postorder. 每次指向某个postorder里的元素,那我们就构建一个以该元素的值为val的tNode. 再去inorder里面找到这个tNode.val, 得到inIndex. 这样我们就可以把in...
* 105. Construct Binary Tree from Inorder and preorder Traversal * 11.20 By Mingyang * 千万不要以为root一定在中间那个点,还是要找一下中间点的位置 * p.left = construct(preorder, preStart + 1, preStart + (k - inStart),inorder, inStart, k - 1); * p.right = construct(preorder, p...
Construct Binary Search Tree from Preorder Traversal in Python - Suppose we have to create a binary search tree that matches the given preorder traversal. So if the pre-order traversal is like [8,5,1,7,10,12], then the output will be [8,5,10,1,7,null,12]