James Pan

原题网址：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

原题网址：https://leetcode.com/problems/invert-binary-tree/ Invert a binary tree. 4 / \ 2 7 / \ / \ 1 3 6 9 to 4 / \ 7 2 / \ / \ 9 6 3 1 思路：递归调用，对左右子节

原题网址：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

原题网址：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

原题网址：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

原题网址：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 in

原题网址：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

原题网址：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

原题网址：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. Example:

原题网址：https://leetcode.com/problems/path-sum-iii/ You are given a binary tree in which each node contains an integer value. Find the number of paths that sum to a given value. The path does

原题网址：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).

原题网址：https://leetcode.com/problems/binary-tree-longest-consecutive-sequence/ Given a binary tree, find the length of the longest consecutive sequence path. The path refers to any sequence

原题网址：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

原题网址：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 definiti

本人原创，如有错误恳请指正，谢谢！ 原题网址https://leetcode.com/problems/count-complete-tree-nodes/ Given a complete binary tree, count the number of nodes.

原题网址：https://leetcode.com/problems/binary-tree-level-order-traversal-ii/ Given a binary tree, return the bottom-up level order traversal of its nodes' values. (ie, from left to right, level by le

原题网址：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.

原题网址：https://leetcode.com/problems/flatten-binary-tree-to-linked-list/ Given a binary tree, flatten it to a linked list in-place. For example, Given 1 / \ 2 5

原题网址：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

原题网址：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.

原题网址：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

原题网址：https://leetcode.com/problems/sum-of-left-leaves/ Find the sum of all left leaves in a given binary tree. Example: 3 / \ 9 20 / \ 15 7 There are two left leaves in t