Implement an iterator over a binary search tree (BST). Your iterator will be initialized with the root node of a BST. Callingnext()will return the next smallest number in the BST. Note:next()andhasNext()should run in average O(1) time and uses O(h) memory, wherehis the height of t...
publicTreeNode searchBST(TreeNode root, intval) {if(root ==null|| root.val==val) {returnroot; } Queue<TreeNode> queue = new LinkedList<TreeNode>(); queue.offer(root);while(!queue.isEmpty()) { TreeNode temp = queue.poll();if(temp !=null&& temp.val==val) {returntemp; }elseif(...
--- //adds a new Node to the tree (in a way of a Binary Search tree): public void add(int data){ insert(this.root, data); } private void insert(Node node, int data){ if (node == null){ //stops the recursion, some node will have to be null sometime.. //also sets the ...
You are given therootof a binary search tree (BST) and an integerval. Find the node in the BST that the node's value equalsvaland return the subtree rooted with that node. If such a node does not exist, returnnull. Example 1: ...
Given a binary tree, return the inorder traversal of its nodes' values. For example: Given binary tree {1,#,2,3}, 1 \ 2 / 3 return [1,3,2]. 栈迭代 复杂度 时间O(b^(h+1)-1) 空间 O(h) 递归栈空间 对于二叉树b=2 思路 ...
Given a binary search tree (BST), find the lowest common ancestor (LCA) of two given nodes in the BST.According to the definition of LCA on Wikipedia:“The lowest common ancestor is defined between two nodes p and q as the lowest node in T that has both p and q as descendants (wher...
/** * Definition for a binary tree node. * type TreeNode struct { * Val int * Left *TreeNode * Right *TreeNode * } */ func isValidBST(root *TreeNode) bool { return dfs(root, nil, nil) } func dfs(root *TreeNode, low *int, high *int) bool { // 空子树必定满足题意 if...
[LeetCode] 98. Validate Binary Search Tree(是否是二叉搜索树) ☆☆☆,描述解析二叉搜索树,其实就是节点n的左孩子所在的树,每个节点都小于节点n。节点n的右孩子所在的树,每个节点都大于节点n。定义子树的最大最小值比如:左孩子要小于父节点;左孩子n的右孩子要大于n
第C++实现LeetCode(108.将有序数组转为二叉搜索树)[LeetCode]108.ConvertSortedArraytoBinarySearchTree将有序数组转为二叉搜索树 Givenanarraywhereelementsaresortedinascendingorder,convertittoaheightbalancedBST. Forthisproblem,aheight-balancedbinarytreeisdefinedasabinarytreeinwhichthedepthofthetwosubtreesofeverynode...
publicTreeNodesearchBST(TreeNode root,intval){while(root!=null){if(root.val>val){root=root.left;}elseif(root.val<val){root=root.right;}else{returnroot;}}returnnull;} 04 第三种解法 我们也可以使用队列来做。将所有节点值依次入队列,在入队列前先判断节点值是否等于val,等于就直接返回当前节点所在...