Trees
Master tree traversal, manipulation, and advanced tree algorithms.
Showing 40 of 40 questions
Easy: 14 Medium: 22 Hard: 4
| Question | Difficulty |
|---|---|
Check if BST is Balanced Check if a binary search tree is height-balanced | Easy |
Closest Value in BST Find the value in BST that is closest to a given target | Easy |
Lowest Common Ancestor in BST Find the lowest common ancestor of two nodes in a binary search tree | Easy |
Range Sum of BST Calculate the sum of all node values within a given range in a BST | Easy |
Search in BST Search for a specific value in a binary search tree | Easy |
BST to Greater Sum Tree Convert BST where each node's value becomes sum of all greater values | Medium |
Construct BST from Preorder Construct a BST from its preorder traversal sequence | Medium |
Convert BST to Sorted Doubly Linked List Convert a binary search tree to a sorted doubly linked list in-place | Medium |
Count Nodes in Complete BST Count the number of nodes in a complete binary search tree efficiently | Medium |
Delete Node in BST Delete a node with given key from a binary search tree | Medium |
Floor and Ceil in BST Find floor and ceiling values for a given key in a BST | Medium |
Inorder Successor in BST Find the inorder successor of a given node in a BST | Medium |
Insert into BST Insert a new node with given value into a binary search tree | Medium |
Kth Largest Element in BST Find the kth largest value in a binary search tree | Medium |
Kth Smallest Element in BST Find the kth smallest value in a binary search tree | Medium |
Find Median of BST Find the median value in a binary search tree | Medium |
Serialize and Deserialize BST Serialize a BST to string and deserialize string back to BST | Medium |
Trim a BST Trim a BST to contain only nodes within a given range | Medium |
Validate BST Determine if a binary tree is a valid binary search tree | Medium |
Recover BST Recover a BST where exactly two nodes have been swapped | Hard |
Convert Sorted Array to Binary Search Tree Convert a sorted array to a height-balanced binary search tree. | Easy |
Diameter of Binary Tree Find the diameter (longest path) of a binary tree. | Easy |
Binary Tree Inorder Traversal Traverse a binary tree in inorder (left -> root -> right) | Easy |
Invert Binary Tree Invert (mirror) a binary tree by swapping left and right children | Easy |
Maximum Depth of Binary Tree Find the maximum depth (height) of a binary tree | Easy |
Path Sum Check if there exists a root-to-leaf path with given sum. | Easy |
Postorder Traversal Traverse binary tree in postorder (left, right, root) | Easy |
Binary Tree Preorder Traversal Traverse a binary tree in preorder (root -> left -> right) | Easy |
Symmetric Tree Check if a binary tree is symmetric around its center. | Easy |
Boundary Traversal of Binary Tree Traverse the boundary of a binary tree in anti-clockwise direction. | Medium |
Construct Binary Tree from Preorder and Inorder Traversal Construct a binary tree from preorder and inorder traversal sequences. | Medium |
Count Good Nodes in Binary Tree Count the number of nodes in a binary tree where the path from root to that node has no nodes with values greater than the current node. | Medium |
Flatten Binary Tree to Linked List Flatten a binary tree into a linked list in-place using preorder traversal. | Medium |
Level Order Traversal Traverse a binary tree level by level from left to right. | Medium |
Lowest Common Ancestor Find the lowest common ancestor of two nodes in a binary tree. | Medium |
Print All Root-to-Leaf Paths Print all root-to-leaf paths in a binary tree | Medium |
Zigzag Level Order Traversal Traverse a binary tree level by level in zigzag order | Medium |
Maximum Path Sum Find the maximum path sum in a binary tree. | Hard |
Serialize and Deserialize Binary Tree Serialize a binary tree to a string and deserialize it back to the original tree | Hard |
Vertical Order Traversal of Binary Tree Traverse a binary tree vertically and return nodes by columns | Hard |