小榕流光的专栏

题目链接：https://leetcode.com/problems/lowest-common-ancestor-of-a-binary-search-tree/Given a binary search tree (BST), find the lowest common ancestor (LCA) of two given nodes in the BST.Accord

题目链接：https://leetcode.com/problems/populating-next-right-pointers-in-each-node/Given a binary tree struct TreeLinkNode { TreeLinkNode *left; TreeLinkNode *right; TreeLinkN

题目链接: https://leetcode.com/problems/binary-tree-upside-down/Given a binary tree where all the right nodes are either leaf nodes with a sibling (a left node that shares the same parent node) or e

题目链接：https://leetcode.com/problems/binary-tree-inorder-traversal/Given a binary tree, return the inorder traversal of its nodes' values.For example:Given binary tree {1,#,2,3}, 1

题目链接: https://leetcode.com/problems/count-univalue-subtrees/Given a binary tree, count the number of uni-value subtrees.A Uni-value subtree means all nodes of the subtree have the same value

题目链接: https://leetcode.com/problems/inorder-successor-in-bst/Given a binary search tree and a node in it, find the in-order successor of that node in the BST.Note: If the given node has no i

题目链接：https://leetcode.com/problems/binary-tree-vertical-order-traversal/Given a binary tree, return the vertical order traversal of its nodes' values. (ie, from top to bottom, column by column).

题目链接：https://leetcode.com/problems/closest-binary-search-tree-value/Given a non-empty binary search tree and a target value, find the value in the BST that is closest to the target.Note:

题目链接: https://leetcode.com/problems/find-leaves-of-binary-tree/Given a binary tree, find all leaves and then remove those leaves. Then repeat the previous steps until the tree is empty.Examp

题目链接：https://leetcode.com/problems/binary-tree-right-side-view/Given a binary tree, imagine yourself standing on the right side of it, return the values of the nodes you can see ordered from top

题目链接：https://leetcode.com/problems/count-complete-tree-nodes/Given a complete binary tree, count the number of nodes.Definition of a complete binary tree from Wikipedia:In a complete binar

题目链接: https://leetcode.com/problems/count-of-smaller-numbers-after-self/You are given an integer array nums and you have to return a new counts array. The counts array has the property where cou

题目链接：https://leetcode.com/problems/verify-preorder-sequence-in-binary-search-tree/Given an array of numbers, verify whether it is the correct preorder traversal sequence of a binary search tree.

题目链接：https://leetcode.com/problems/path-sum/Given a binary tree and a sum, determine if the tree has a root-to-leaf path such that adding up all the values along the path equals the given sum.

题目链接：https://leetcode.com/problems/balanced-binary-tree/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

题目链接：https://leetcode.com/problems/kth-smallest-element-in-a-bst/Given a binary search tree, write a function kthSmallest to find the kth smallest element in it.Note: You may assume k is

题目链接:https://leetcode.com/problems/closest-binary-search-tree-value-ii/Given a non-empty binary search tree and a target value, find k values in the BST that are closest to the target.Note:

题目链接：https://leetcode.com/problems/same-tree/Given two binary trees, write a function to check if they are equal or not.Two binary trees are considered equal if they are structurally identic

题目链接：https://leetcode.com/problems/find-the-duplicate-number/Given an array nums containing n + 1 integers where each integer is between 1 and n (inclusive), prove that at least one duplicate nu

题目链接:https://leetcode.com/problems/serialize-and-deserialize-binary-tree/Serialization is the process of converting a data structure or object into a sequence of bits so that it can be stored in

题目链接: https://leetcode.com/problems/largest-bst-subtree/Given a binary tree, find the largest subtree which is a Binary Search Tree (BST), where largest means subtree with largest number of node

题目链接：https://leetcode.com/problems/validate-binary-search-tree/Given a binary tree, determine if it is a valid binary search tree (BST).Assume a BST is defined as follows:The left subtre

题目链接：https://leetcode.com/problems/construct-binary-tree-from-inorder-and-postorder-traversal/Given inorder and postorder traversal of a tree, construct the binary tree.Note:You may assume

题目链接：https://leetcode.com/problems/construct-binary-tree-from-preorder-and-inorder-traversal/Given preorder and inorder traversal of a tree, construct the binary tree.Note:You may assume t

题目链接：https://leetcode.com/problems/binary-tree-level-order-traversal/Given a binary tree, return the level order traversal of its nodes' values. (ie, from left to right, level by level).For

题目链接：https://leetcode.com/problems/minimum-depth-of-binary-tree/Given a binary tree, find its minimum depth.The minimum depth is the number of nodes along the shortest path from the root nod

题目链接：https://leetcode.com/problems/binary-search-tree-iterator/Implement an iterator over a binary search tree (BST). Your iterator will be initialized with the root node of a BST.Calling ne

题目链接：https://leetcode.com/problems/populating-next-right-pointers-in-each-node-ii/Follow up for problem "Populating Next Right Pointers in Each Node".What if the given tree could be any bina

题目链接：https://leetcode.com/problems/binary-tree-postorder-traversal/Given a binary tree, return the postorder traversal of its nodes' values.For example:Given binary tree {1,#,2,3}, 1

题目链接：https://leetcode.com/problems/lowest-common-ancestor-of-a-binary-tree/   Given a binary tree, find the lowest common ancestor (LCA) of two given nodes in the tree.According to the defin

题目链接：https://leetcode.com/problems/binary-tree-preorder-traversal/Given a binary tree, return the preorder traversal of its nodes' values.For example:Given binary tree {1,#,2,3}, 1

题目链接：https://leetcode.com/problems/convert-sorted-array-to-binary-search-tree/Given an array where elements are sorted in ascending order, convert it to a height balanced BST.思路：前面有一题将有序链表转换

题目链接：https://leetcode.com/problems/maximum-depth-of-binary-tree/Given a binary tree, find its maximum depth.The maximum depth is the number of nodes along the longest path from the root node

题目链接: https://leetcode.com/problems/verify-preorder-serialization-of-a-binary-tree/One way to serialize a binary tree is to use pre-order traversal. When we encounter a non-null node, we record

题目链接: https://leetcode.com/problems/binary-tree-maximum-path-sum/Given a binary tree, find the maximum path sum.For this problem, a path is defined as any sequence of nodes from some startin

题目链接：https://leetcode.com/problems/recover-binary-search-tree/Two elements of a binary search tree (BST) are swapped by mistake.Recover the tree without changing its structure.Note:A sol

题目链接：https://leetcode.com/problems/path-sum-ii/Given a binary tree and a sum, find all root-to-leaf paths where each path's sum equals the given sum.For example:Given the below binary tree a

题目链接：https://leetcode.com/problems/sum-root-to-leaf-numbers/Given a binary tree containing digits from 0-9 only, each root-to-leaf path could represent a number.An example is the root-to-l

题目链接：https://leetcode.com/problems/binary-tree-paths/Given a binary tree, return all root-to-leaf paths.For example, given the following binary tree: 1 / \2 3 \ 5

题目链接：https://leetcode.com/problems/symmetric-tree/Given a binary tree, check whether it is a mirror of itself (ie, symmetric around its center).For example, this binary tree is symmetric: