The right subtree of a node contains only nodes with keys greater than the node's key. Both the left and right subtrees must also be binary search trees. Example 1: 2 /\1 3 Binary tree[2,1,3], return true. Example 2: 1 /\2 3 Binary tree[1,2,3], return false. 2、边界条件...
Given a binary tree, find the lowest common ancestor (LCA) of two given nodes in the tree. 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 (where we allow...
LeetCode 110. Balanced Binary Tree (平衡二叉树) Given a binary tree, determine if it is height-balanced. For this problem, a height-balanced binary tree is defined as a binary tree in which the depth of the two subtrees ofeverynode never differ by more than 1. 题目标签:Tree 这道题目...
work. You just need to ensure that a binary tree can be serialized to a string and this string can be deserialized to the original tree structure. Example: You may serialize the following tree: 1 / \ 2 3 / \ 4 5 as "[1,2,3,null,null,4,5]" Clarification: The above format is ...
Binary Tree Path Sum (easy) All Paths for a Sum (medium) Sum of Path Numbers (medium) Path With Given Sequence (medium) Count Paths for a Sum (medium) 9. Pattern: Two Heaps,双堆类型 很多问题中,我们被告知,我们拿到一大把可以分成两队的数字。为了解决这个问题,我们感兴趣的是,怎么把数字分成...
8. Pattern: Tree Depth First Search,树上的DFS 经典题目: Binary Tree Path Sum (easy) All Paths for a Sum (medium) Sum of Path Numbers (medium) Path With Given Sequence (medium) Count Paths for a Sum (medium) 9. Pattern: Two Heaps,双堆类型 经典题目: Find the Median of a Number Str...
Given the root of a binary tree, return the inorder traversal of its nodes' values. Example 1: Input: root = [1,null,2,3] Output: [1,3,2] Explanation: Example 2: Input: root = [1,2,3,4,5,null,8,null,null,6,7,9] Output: [4,2,6,5,7,1,3,9,8] Explanation: Example...
701. Insert into a Binary Search Tree You are given therootnode of a binary search tree (BST) and avalueto insert into the tree. Returnthe root node of the BST after the insertion. It isguaranteedthat the new value does not exist in the original BST....
我正在研究LeetCode问题https://leetcode.com/problems/binary-tree-preorder-traversal。 当我在solution方法中创建堆栈并将其传递给traverse方法时,编译器给出error: object cannot be converted to TreeNode (type)。 但是,当我将该行与push(root)行一起放在traverse方法中时,错误就消失了。
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