1. Problem Statement Given a list of intervals, merge all the overlapping intervals and return a list of non-overlapping intervals. An interval is represented as a pair of integers [start, end]. Example 2. Understanding the Problem The core idea is to combine intervals that share common points. If two intervals [a,b] and [c,d] overlap, their…

In this tutorial, we will explore the concept of intervals, which are essential in solving many algorithmic and interview problems, particularly those involving time, tasks, or scheduling. One of the most important subtopics in intervals is overlapping intervals, often asked in coding interviews. 1. What is an Interval? An interval is a range defined by…

1. What Is a Symmetric Tree? A symmetric tree is a binary tree that is a mirror image of itself around its center. 2. Visual Example of a Symmetric Tree The left subtree is a mirror reflection of the right subtree. 3. Visual Example of an Asymmetric Tree Here, symmetry is broken because one node…

1. What is a Binary Search Tree? A Binary Search Tree (BST) is a type of binary tree where: Example of a valid BST: Example of an invalid BST: 2. What Does It Mean to Validate a BST? Validation means checking whether a binary tree obeys the BST property. A common mistake is to check…

1. Objective Given a value, determine whether it exists in a Binary Search Tree (BST).The search operation leverages the inherent sorted structure of a BST to perform an efficient lookup. 2. Binary Search Tree Property Recap In a BST: This structure allows for binary search, which reduces the search space by half with each comparison.…

1. Objective The goal is to insert a new value into a Binary Search Tree while maintaining the BST property, which states: 2. Rules for Insertion To insert a value into a BST: 3. Visual Example Insert the value 45 into the following BST: Step-by-step: Updated Tree: 4. Java Implementation Step 1: Tree Node Class…

1. What is a Binary Search Tree (BST)? A Binary Search Tree (BST) is a special kind of binary tree that maintains a specific order among its elements (nodes), which makes it efficient for operations like search, insert, and delete. 2. Definition: A Binary Search Tree is a binary tree in which: This property is…

1. Problem Statement Given a binary tree, find the maximum value among all the nodes using recursion. 2. Understanding the Problem In a binary tree, each node has: We need to traverse all nodes and return the maximum value present in the tree. This tree is not necessarily a Binary Search Tree (BST), so we…

1. What is Level Order Traversal? Level Order Traversal is a type of Breadth-First Search (BFS) where we traverse a binary tree level by level, starting from the root and moving to the children from left to right. 2. Example Given this binary tree: The level order traversal would be: 3. Why Use Level Order…

1. Introduction Postorder traversal follows this visiting order: In the recursive version, the call stack takes care of visiting nodes in the correct order. But in iterative postorder traversal, we must manually simulate the stack behavior. 2. Why Postorder Is Tricky Iteratively Unlike preorder (Root → Left → Right) and inorder (Left → Root →…