Try it on GfG Practice Given a Singly Linked List which has data members sorted in ascending order. Construct a Balanced Binary Search Tree which has same data members as the given Linked List. Examples: Input: Linked List 1->2->3 Output: A Balanced BST 2 / \ 1 3 Input: Linked List…

Try it on GfG Practice Given a binary search tree and a key(node) value, find the ceil value for that particular key value. Please note that we have already discussed floor in BST Example: 8 / \ 4 12 / \ / \ 2 6 10 14 Key: 11 Ceil: 12 Key: 1 Ceil: 2 Key: 6 Ceil: 6 Key: 15 Ceil: -1 There are numerous…

Given an array and an integer K. We need to find the maximum of every segment of length K which has no duplicates in that segment. Examples: Input : a[] = {1, 2, 2, 3, 3}, K = 3. Output : 1 3 2 For segment (1, 2, 2), Maximum = 1. For segment (2, 2, 3), Maximum = 3. For segment (2, 3, 3), Maximum =…

Given two values n1 and n2 where n1 < n2 and a root pointer to a Binary Search Tree. The task is to find all the keys of the tree in the range n1 to n2 in increasing order. Examples: Input: n1 = 10 , n2 = 22 Output: 12, 20 and 22. Explanation: The keys are 4, 8, 12, 20, and 22, So keys in range 10…

Try it on GfG Practice Given a Binary Search Tree (BST) with Two nodes swapped, the task is to recover the original BST. Input: Output: Explanation: The nodes 20 and 8 were swapped. Input: Output: Explanation: The nodes 10 and 5 were swapped. Table of Content [Naive Approach] Inorder Traversal and…

Try it on GfG Practice AVL tree is a self-balancing Binary Search Tree (BST) where the difference between heights of left and right subtrees cannot be more than one for all nodes. Insertion in an AVL Tree follows the same basic rules as in a Binary Search Tree (BST): A new key is placed in its…

Try it on GfG Practice Given a binary tree and a target, find the number of nodes in the minimum sub-tree with the given sum equal to the target which is also a binary search tree. Examples: Input: 13 / \ 5 23 / \ / \ N 17 N N / 16 Target: 38 Output: 3 Explanation: 5, 17, 16 is the smallest subtree…

Try it on GfG Practice Given a sorted array key [0.. n-1] of search keys and an array freq[0.. n-1] of frequency counts, where freq[i] is the number of searches for keys[i]. Construct a binary search tree of all keys such that the total cost of all the searches is as small as possible. The cost of a…

Try it on GfG Practice Given a Balanced Binary Search Tree and a target sum, the task is to check if there exist a pair in BST with sum equal to the target sum. Any modification to the Binary Search Tree is not allowed. Input: Output: True Explanation: The node with values 15 and 20 form a pair…

Try it on GfG Practice Given a BST, the task is to delete a node in this BST, which can be broken down into 3 scenarios: Case 1. Delete a Leaf Node in BST Case 2. Delete a Node with Single Child in BST Deleting a single child node is also simple in BST. Copy the child to the node and delete the…

Given Preorder traversal of a Binary Search Tree. Then the task is to print leaf nodes of the Binary Search Tree from the given preorder. Examples : Input : preorder[] = {890, 325, 290, 530, 965}; Output : 290 530 965 Explanation: Below is the representation of BST using preorder array. Approach: To…

Try it on GfG Practice Given a Binary Search Tree (BST) and a positive integer k, find the k’th smallest element in the Binary Search Tree. Example: Input: k = 3 Output: 10 Explanation: The inorder traversal of given BST is [4, 8, 10, 12, 14, 20, 22] and its 3rd smallest element is 10. Approach: The…

Given a Binary Tree, write a function that returns the size of the largest subtree which is also a Binary Search Tree (BST). If the complete Binary Tree is BST, then return the size (number of nodes) of the whole tree. Examples: Input: Output: 3 The following subtree is the maximum size BST subtree…

Try it on GfG Practice Given two nodes n1 and n2 of a Binary Search Tree, find the Lowest Common Ancestor (LCA). You may assume that both values exist in the tree. The Lowest Common Ancestor between two nodes n1 and n2 is defined as the lowest node that has both n1 and n2 as descendants (where we…

Try it on GfG Practice Given a binary tree. The task is to find the top view of the binary tree. The top view of a binary tree is the set of nodes visible when the tree is viewed from the top. Note: Return the nodes from the leftmost node to the rightmost node.If two nodes are at the same position…

Given a binary search tree of size N > 1, the task is to find the minimum absolute difference between any two nodes. Examples: Input: 5 / \ 3 7 / \ / \ 2 4 6 8 Output: 1 Difference between all the consecutive nodes if sorted is 1. Thus, the answer is 1. Input: 1 \ 6 Output: 5 Brute Force Using…

Try it on GfG Practice Given an array of distinct positive integers, the task is to find the maximum product of increasing subsequence of size 3, i.e., we need to find arr[i]*arr[j]*arr[k] such that arr[i] < arr[j] < arr[k] and i < j < k < n Examples: Input: arr[] = {10, 11, 9, 5, 6, 1, 20} Output:…

Try it on GfG Practice Given a Binary tree and number of nodes in the tree, the task is to find the number of pairs violating the BST property. Binary Search Tree is a node-based binary tree data structure which has the following properties: The left subtree of a node contains only nodes with keys…

Try it on GfG Practice Given a BST, transform it into a greater sum tree where each node contains the sum of all nodes greater than that node. Example: Input: Output: Explanation: The above tree represents the greater sum tree where each node contains the sum of all nodes greater than that node in…

Try it on GfG Practice Given a Binary Search Tree (BST) and a range [min, max], the task is to remove all keys which are outside the given range. The modified tree should also be BST. Examples: Input : low = -10, high = 13 Output: Explanation: All keys outside the range [-10, 13] are removed and the…

Try it on GfG Practice Given a Binary Search Tree which is also a Complete Binary Tree. The problem is to convert a given BST into a Special Max Heap with the condition that all the values in the left subtree of a node should be less than all the values in the right subtree of the node. This…

Try it on GfG Practice Given a Binary Tree, the task is to find the maximum sum path from a leaf to a root. Example : Input: Output: 60 Explanantion: There are three leaf to root paths 20->30->10, 5->30->10 and 15->10. The sums of these three paths are 60, 45 and 25 respectively. The maximum of them…

Try it on GfG Practice Given Preorder traversal of a Binary Search Tree. Then the task is to print leaf nodes of the Binary Search Tree from the given preorder. Examples: Input: preorder[] = [4, 2, 1, 3, 6, 5] Output: [1, 3, 5] Explaination: 1, 3 and 5 are the leaf nodes as shown in the figure.…

Try it on GfG Practice Given an array of numbers, the task is to check if the given array can represent the preorder traversal of a Binary Search Tree. Examples: Input: pre[] = [40, 30, 35, 80, 100] Output: true Explanation: Given array can represent preorder traversal of below tree Input: pre[] =…

Given a Binary Search Tree with unique node values and a target value. You have to find the node whose data is equal to the target and return the sum of all descendant (of target) node's data which are vertically below the target node. Initially, you are at the root node. Note: If the target node is…

Try it on GfG Practice Given an array of integers, replace every element with the least greater element on its right side in the array. If there are no greater elements on the right side, replace it with -1. Examples: Input: [8, 58, 71, 18, 31, 32, 63, 92, 43, 3, 91, 93, 25, 80, 28] Output: [18, 63,…

Try it on GfG Practice Given a Binary Search Tree (BST), the task is to modify it so that all greater and equal values in the given BST are added to every node. Examples: Input: Output: Explanation: The above tree represents the greater sum tree where each node contains the sum of all nodes greater…

Try it on GfG Practice Given the root of binary search tree (BST) and an integer target, the task is to find if there exist a pair of elements such that their sum is equal to given target. Example: Input: target = 12 Output: True Explanation: In the binary tree above, there are two nodes (8 and 4)…

Try it on GfG Practice Given a sorted array. The task is to convert it into a Balanced Binary Search Tree (BST). Return the root of the BST. Examples: Input: arr[] = {10, 20, 30} Output: Explanation: The above sorted array converted to Balanced Binary Search Tree. Input: arr[] = {1, 2, 3, 4, 5, 6,…

Try it on GfG Practice Given a BST (Binary Search Tree) that may be unbalanced, the task is to convert it into a balanced BST that has the minimum possible height. Examples: Input: Output: Explanation: The above unbalanced BST is converted to balanced with the minimum possible height. Input: Output:…

Given an array representing preorder traversal of BST, print its postorder traversal. Examples: Input : 40 30 35 80 100 Output : 35 30 100 80 40 Input : 40 30 32 35 80 90 100 120 Output : 35 32 30 120 100 90 80 40 Prerequisite: Construct BST from given preorder traversal Simple Approach: A simple…

Try it on GfG Practice Given two Binary Search Trees, find common nodes in them. In other words, find the intersection of two BSTs. Example: Input: root1: 5 / \ 1 10 / \ / 0 4 7 \ 9 root2: 10 / \ 7 20 / \ 4 9 Output: 4 7 9 10 Recommended Practice Find Common Nodes in two BSTs Try It! Naive Approach:…

Try it on GfG Practice Given a Binary search Tree that contains positive integer values greater than 0. The task is to check whether the BST contains a dead end or not. Here Dead End means, we are not able to insert any element after that node. Examples: Input: root[] = [8, 5, 9, 2, 7, N, N, 1]…

Try it on GfG Practice Given the root of a binary tree. Check whether it is a Binary Search Tree or not. A Binary Search Tree (BST) is a node-based binary tree data structure with the following properties. All keys in the left subtree are smaller than the root and all keys in the right subtree are…

Try it on GfG Practice Given a BST, the task is to search a node in this BST. For searching a value in BST, consider it as a sorted array. Now we can easily perform search operation in BST using Binary Search Algorithm. Input: Root of the below BST Output: True Explanation: 8 is present in the BST…

Try it on GfG Practice Given the root of a Binary Search Tree. The task is to find the minimum valued element in this given BST. Example: Input: Output: 1 Explanation: The minimum element in the given BST is 1. Input: Output: 2 Explanation: The minimum element in the given BST is 2 Table of Content…

Try it on GfG Practice Given a Binary Search Tree (BST) and a positive integer k, the task is to find the kth largest element in the Binary Search Tree. Example: Input: k = 3 Output: 14 Explanation: If we sort the BST in decreasing order, then it will become 22, 20, 14, 12, 10, 8, 4. 14 is the 3rd…

Try it on GfG Practice Given a Binary Search Tree (BST) and a range [l, h], the task is to count the number of nodes in the BST that lie in the given range. Examples: Input: Output: 3 Explanation: There are three nodes in range [5, 45] = 5, 10 and 40. Input: Output: 4 Explanation: There are four…

Try it on GfG Practice In the Binary Tree, the Inorder successor of a node is the next node in the Inorder traversal of the Binary Tree. Inorder Successor is NULL for the last node in Inorder traversal. Example: In the below diagram, inorder successor of 8 is 10, inorder successor of 10 is 12 and…

Try it on GfG Practice Given a Binary Tree, the task is to convert it to a Binary Search Tree. The conversion must be done in such a way that keeps the original structure of the Binary Tree. Examples Input: Output: Explanation: The above Binary tree is converted to Binary Search tree by keeping the…