🚀 Java Core to Advanced

A structured, step-by-step roadmap to master Java from fundamentals to advanced Data Structures & Algorithms — with clean implementations and interview-focused practice.

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👋 Who Is This For?

✔ Beginners starting Java
✔ Students preparing for placements
✔ Developers strengthening fundamentals
✔ Interview preparation
✔ Anyone who prefers structured learning

This is not random code.
This is organized progression.

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🗺 Complete Java + DSA Learning Roadmap

START
  │
  ▼
┌──────────────────────────┐
│ 01. Java Basics          │
│ Variables, Loops, Arrays │
└──────────────────────────┘
  │
  ▼
┌──────────────────────────┐
│ 02. OOP (Core Java)      │
│ Classes, Inheritance     │
│ Polymorphism, Interfaces │
└──────────────────────────┘
  │
  ▼
┌──────────────────────────┐
│ 03. Time & Space         │
│ Big-O, Complexity        │
└──────────────────────────┘
  │
  ▼
┌──────────────────────────┐
│ 04. Recursion            │
│ Call Stack, Base Case    │
└──────────────────────────┘
  │
  ▼
┌──────────────────────────┐
│ 05. Divide & Conquer     │
│ Merge Sort, Quick Sort   │
└──────────────────────────┘
  │
  ▼
┌──────────────────────────┐
│ 06. Linear DS            │
│ ArrayList, LinkedList    │
│ Stack, Queue             │
└──────────────────────────┘
  │
  ▼
┌──────────────────────────┐
│ 07. Hashing              │
│ HashMap, HashSet         │
└──────────────────────────┘
  │
  ▼
┌──────────────────────────┐
│ 08. Trees                │
│ Binary Tree, BST, Heaps  │
└──────────────────────────┘
  │
  ▼
┌──────────────────────────┐
│ 09. Greedy & Backtracking│
└──────────────────────────┘
  │
  ▼
┌──────────────────────────┐
│ 10. Graphs               │
│ BFS, DFS, Topo Sort      │
└──────────────────────────┘
  │
  ▼
┌──────────────────────────┐
│ 11. Dynamic Programming  │
│ Memoization, Tabulation  │
└──────────────────────────┘
  │
  ▼
┌──────────────────────────┐
│ 12. Advanced Structures  │
│ Tries, Segment Trees     │
└──────────────────────────┘
  │
  ▼
🎯 INTERVIEW READY

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📂 Repository Structure

java-core-to-advanced/
│
├── 01-basics/
├── 02-variables-and-data-types/
├── 03-operators/
├── 04-conditional-statements/
├── 05-loops-and-flow-control/
├── 06-pattern-programs/
├── 07-functions-and-methods/
├── 08-arrays/
├── 09-sorting/
├── 10-2d-arrays/
├── 11-strings/
├── 12-bit-manipulation/
│
├── 13-oops/
├── 14-time-and-space-complexity/
├── 15-recursion/
├── 16-divide-and-conquer/
├── 17-arraylist/
├── 18-linked-list/
├── 19-stack/
├── 20-queue/
├── 21-hashing/
├── 22-binary-trees/
├── 23-bst/
├── 24-heaps/
├── 25-greedy/
├── 26-backtracking/
├── 27-graphs/
├── 28-dynamic-programming/
├── 29-tries/
├── 30-segment-trees/
│
└── README.md

Each folder contains:

• Clean Java implementations
• Proper comments
• Structured naming (PascalCase)
• Practice problems
• Progressive difficulty

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🧪 Sample Code

Check Even or Odd (Bitwise)

public static boolean isEven(int num) {
    return (num & 1) == 0;
}

Get i-th Bit

public static int getIthBit(int num, int i) {
    return (num >> i) & 1;
}

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🛠 How To Use

1️⃣ Clone Repository

git clone https://github.com/PavithraSharma14/java-core-to-advanced.git
cd java-core-to-advanced

2️⃣ Open in IDE

Recommended:

• IntelliJ IDEA
• VS Code
• Eclipse

3️⃣ Follow the Roadmap Order

Start from:

01-basics → move sequentially

Do not skip complexity + recursion before advanced topics.

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📈 Progress Tracker

Stage	Topic	Status
1	Basics	✅ Completed
2	OOP	🔄 Next
3	Time & Space	⏳ Planned
4	Recursion	⏳ Planned
5	DSA	⏳ In Progress

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🎯 Learning Strategy

To maximize results:

1. Read the concept
2. Run the code
3. Modify it
4. Solve practice problems
5. Re-implement without looking
6. Track your complexity

Consistency > Speed
Structure > Random Learning

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💼 Why This Repository Stands Out

• Structured learning path
• Interview-focused progression
• Clean naming conventions
• Progressive module system
• Covers fundamentals to advanced DSA

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🤝 Contributing

Contributions are welcome.

Guidelines:

• Follow folder structure
• Maintain clean code
• Use PascalCase for file names
• Add meaningful comments
• Keep logic readable

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📜 License

MIT License

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⭐ If You Find This Helpful

If this repository helped you understand Java concepts, consider giving it a ⭐.

It helps the repository reach more learners.