☕ Java Programming and Data Structures & Algorithms

Welcome to the Java Programming, Data Structures, and Algorithms repository!

This repository is a complete guide for learning Java programming, understanding core data structures, and mastering essential algorithms — all in one place. It’s designed for students, beginners, and professionals revisiting fundamental computer science concepts.

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🚀 Features

• ✅ Step-by-step Java examples
• 🧩 Data Structures implemented from scratch
• ⚙️ Core and advanced Algorithms
• 💡 Clear explanations and code comments
• 🧪 Example inputs/outputs for clarity
• 🏗️ Well-organized modular project structure
• ⚡ Beginner-friendly and ready to run

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🧰 Tech Stack

Component	Description
Language	Java (JDK 17 or later)
Compiler	javac (Java Compiler)
IDE Support	IntelliJ IDEA, VS Code, Eclipse, NetBeans
Build Tools	Maven / Gradle (optional)

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📂 Repository Structure

Java-Programming-DataStructures-Algorithms/
├── README.md
├── 01_Basics/
│   ├── HelloWorld.java
│   ├── Operators.java
│   ├── ControlStatements.java
│   ├── Loops.java
│   ├── ArraysIntro.java
│   └── InputOutput.java
│
├── 02_ObjectOrientedProgramming/
│   ├── ClassesObjects.java
│   ├── InheritanceDemo.java
│   ├── Polymorphism.java
│   ├── Encapsulation.java
│   └── Abstraction.java
│
├── 03_Data_Structures/
│   ├── Arrays/
│   │   ├── LinearSearch.java
│   │   └── BinarySearch.java
│   ├── LinkedLists/
│   │   ├── SinglyLinkedList.java
│   │   ├── DoublyLinkedList.java
│   │   └── CircularLinkedList.java
│   ├── Stacks/
│   │   ├── StackUsingArray.java
│   │   └── StackUsingLinkedList.java
│   ├── Queues/
│   │   ├── QueueUsingArray.java
│   │   └── QueueUsingLinkedList.java
│   ├── Trees/
│   │   ├── BinaryTree.java
│   │   ├── BinarySearchTree.java
│   │   └── TreeTraversal.java
│   ├── Graphs/
│   │   ├── GraphAdjacencyList.java
│   │   └── GraphAdjacencyMatrix.java
│   ├── Hashing/
│   │   ├── HashMapDemo.java
│   │   └── HashSetDemo.java
│   └── Heaps/
│       ├── MinHeap.java
│       └── MaxHeap.java
│
├── 04_Algorithms/
│   ├── Searching/
│   │   ├── LinearSearch.java
│   │   └── BinarySearch.java
│   ├── Sorting/
│   │   ├── BubbleSort.java
│   │   ├── SelectionSort.java
│   │   ├── InsertionSort.java
│   │   ├── MergeSort.java
│   │   └── QuickSort.java
│   ├── Recursion/
│   │   ├── Factorial.java
│   │   ├── Fibonacci.java
│   │   └── TowerOfHanoi.java
│   ├── DivideAndConquer/
│   │   └── BinarySearchRecursive.java
│   ├── Greedy/
│   │   ├── ActivitySelection.java
│   │   └── FractionalKnapsack.java
│   ├── DynamicProgramming/
│   │   ├── FibonacciDP.java
│   │   ├── LongestCommonSubsequence.java
│   │   ├── Knapsack01.java
│   │   └── CoinChange.java
│   ├── GraphAlgorithms/
│   │   ├── BFS.java
│   │   ├── DFS.java
│   │   ├── Dijkstra.java
│   │   ├── Kruskal.java
│   │   ├── Prim.java
│   │   └── TopologicalSort.java
│   └── Backtracking/
│       ├── NQueens.java
│       └── SudokuSolver.java
│
└── 05_Extras/
    ├── FileHandling.java
    ├── ExceptionHandling.java
    ├── LambdaExpressions.java
    └── CollectionsFrameworkDemo.java

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📘 Topics Covered

🔹 Java Fundamentals

• Variables, Data Types, Operators
• Control Statements (if, switch, loops)
• Methods and Recursion
• Arrays and Strings
• Input/Output and Exception Handling

🔹 Object-Oriented Programming (OOP)

• Classes and Objects
• Constructors, this & super keywords
• Inheritance, Polymorphism, Encapsulation, Abstraction
• Interfaces and Abstract Classes
• Packages and Access Modifiers

🔹 Data Structures

• Arrays & Strings
• Linked Lists (Singly, Doubly, Circular)
• Stacks and Queues
• Trees (Binary Tree, BST, Traversals)
• Heaps (Min/Max)
• Graphs (Adjacency List / Matrix, BFS, DFS)
• Hash Maps, Sets, and Priority Queues

🔹 Algorithms

🧠 Searching Algorithms

• Linear Search
• Binary Search (Iterative & Recursive)

🌀 Sorting Algorithms

• Bubble Sort
• Selection Sort
• Insertion Sort
• Merge Sort
• Quick Sort
• Heap Sort
• Counting Sort
• Radix Sort

🔁 Recursion & Backtracking

• Factorial, Fibonacci
• Tower of Hanoi
• N-Queens Problem
• Sudoku Solver

🔗 Divide and Conquer

• Binary Search
• Merge Sort
• Quick Sort

💰 Greedy Algorithms

• Activity Selection
• Fractional Knapsack
• Huffman Coding
• Job Sequencing

⚙️ Dynamic Programming

• Fibonacci (DP Approach)
• Longest Common Subsequence (LCS)
• 0/1 Knapsack
• Coin Change Problem
• Matrix Chain Multiplication
• Longest Increasing Subsequence

🌐 Graph Algorithms

• Breadth First Search (BFS)
• Depth First Search (DFS)
• Dijkstra’s Algorithm
• Kruskal’s Minimum Spanning Tree
• Prim’s Algorithm
• Topological Sorting
• Bellman-Ford Algorithm
• Floyd-Warshall Algorithm

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⚡ Quick Start

# Clone the repository
git clone https://github.com/SatinderSinghSall/Java-Programming-DataStructures-Algorithms.git

# Navigate to the project folder
cd Java-Programming-DataStructures-Algorithms

# Compile and run an example
javac 03_Data_Structures/LinkedLists/SinglyLinkedList.java
java 03_Data_Structures.LinkedLists.SinglyLinkedList

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🧪 Example Program

SinglyLinkedList.java

public class SinglyLinkedList {
    static class Node {
        int data;
        Node next;
        Node(int data) { this.data = data; }
    }

    public static void printList(Node head) {
        Node current = head;
        while (current != null) {
            System.out.print(current.data + " -> ");
            current = current.next;
        }
        System.out.println("NULL");
    }

    public static void main(String[] args) {
        Node head = new Node(10);
        head.next = new Node(20);
        head.next.next = new Node(30);

        printList(head);
    }
}

Output:

10 -> 20 -> 30 -> NULL

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🧑‍💻 Author

Satinder Singh Sall 💼 Full-Stack Developer | Programmer | Code Enthusiast 🔗 Portfolio 🔗 GitHub 📧 satindersinghsall111@gmail.com

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⭐ Contributing

Contributions are always welcome! To contribute:

1. Fork the repository 🍴
2. Create a new branch (feature/your-feature)
3. Commit your changes
4. Submit a Pull Request 🚀

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💡 "First, solve the problem. Then, write the code." — John Johnson

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