# LeetCode 297. Serialize and Deserialize Binary Tree

Description 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…

# LeetCode 116. Populating Next Right Pointers in Each Node

Description https://leetcode.com/problems/search-a-2d-matrix-ii/ You are given a perfect binary tree where all leaves are on the same level, and every parent has two children.…

# LeetCode 103. Binary Tree Zigzag Level Order Traversal

Description https://leetcode.com/problems/binary-tree-zigzag-level-order-traversal/ Given a binary tree, return the zigzag level order traversal of its nodes’ values. (ie, from left to right, then…

# LeetCode 105. Construct Binary Tree from Preorder and Inorder Traversal

Description 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 that duplicates do…

# LeetCode 230. Kth Smallest Element in a BST

Description 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. Example 1: Input: root…

# LeetCode 94. Binary Tree Inorder Traversal

Description https://leetcode.com/problems/binary-tree-inorder-traversal/ Given a binary tree, return the inorder traversal of its nodes’ values. Example: Input: [1,null,2,3] 1 \ 2 / 3…

# LeetCode 1008. Construct Binary Search Tree from Preorder Traversal

Description https://leetcode.com/problems/construct-binary-search-tree-from-preorder-traversal/ Return the root node of a binary search tree that matches the given preorder traversal. (Recall that a binary search tree is a…

# LeetCode 543. Diameter of Binary Tree

Description https://leetcode.com/problems/diameter-of-binary-tree/ Given a binary tree, you need to compute the length of the diameter of the tree. The diameter…

# LeetCode 108. Convert Sorted Array to Binary Search Tree

Description 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. For…

# LeetCode 98. Validate Binary Search Tree

Description 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…