Data Structures & Algorithms Repository

This repository contains implementations of various data structures and solutions to coding problems, primarily from LeetCode. It serves as a comprehensive collection of fundamental computer science concepts and algorithmic problem-solving techniques.

📁 Repository Structure

Core Data Structures

• BinaryTree.java - Binary tree implementation with basic operations
• CircularLinkedList.java - Circular linked list implementation
• DoublyLinkedList.java - Doubly linked list with forward and backward traversal
• singlyLinkedList.Java - Basic singly linked list implementation
• Queue.java - Queue data structure implementation
• Stack.java - Stack implementation with standard operations
• StackUsingArray.java - Array-based stack implementation

Algorithm Implementations

• NextGreaterElement.java - Finding next greater element in arrays
• ReverseStringInStack.java - String reversal using stack

LeetCode Solutions

The Leetcode/ folder contains solutions to various LeetCode problems organized by categories:

Array & String Problems

• Two Sum, Three Sum
• Best Time to Buy and Sell Stock (I & II)
• Move Zeroes, Rotate Array
• Valid Palindrome, Valid Anagram
• Group Anagrams, First Unique Character
• And many more...

Linked List Problems

• Reverse Linked List
• Remove Nth Node from End
• Delete Middle Node
• Merge K Sorted Lists

Binary Tree Problems

• In-order, Pre-order, Post-order Traversals
• Tree node implementation

Binary Search Problems

• Find Smallest Letter Greater Than Target

🚀 Getting Started

This repository is written in Java. To run any of the implementations:

1. Clone the repository
2. Compile the Java files using javac
3. Run the desired program using java

Example:

javac BinaryTree.java
java BinaryTree

📚 Purpose

This repository serves as:

• A reference for common data structure implementations
• Practice solutions for coding interviews
• Study material for algorithms and data structures
• A collection of LeetCode problem solutions with explanations

🤝 Contributing

Feel free to add more data structure implementations or LeetCode solutions. Make sure to follow consistent coding style and add appropriate comments.

📝 Notes

Each implementation focuses on clarity and educational value, making it easy to understand the underlying concepts and algorithms.