📌 Singly Linked List

A detailed implementation and theoretical explanation of the Singly Linked List, covering node structure, memory allocation, pointer concepts, and fundamental operations. This repository combines conceptual understanding with program-based implementation for learning data structures effectively.

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📖 Contents

🔹 1. Introduction

• A linked list is a collection of nodes

• Each node contains:

  • Data field
  • Next pointer (link field)

• Nodes are connected sequentially using pointers

• The last node points to NULL, indicating the end of the list

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🔹 2. Key Concepts

• Head Pointer → Points to the first node
• Tail Node → Last node (points to NULL)
• Null List → List with zero elements
• Dynamic Memory Allocation using malloc()
• Nodes are stored in non-contiguous memory

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🔹 3. Node Structure (C/C++)

typedef struct ListNode {
    int data;
    struct ListNode *next;
} Node;

• data → stores value
• next → stores address of next node

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🔹 4. Creating an Empty List

void createEmptyList(Node **head) {
    *head = nullptr;
}

• Uses pointer to pointer (Node **head)
• Initializes list as empty (NULL)
• Demonstrates call by reference

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🔹 5. Important Concepts Explained

✔️ Typedef

• Simplifies struct naming
• Example: Node instead of struct ListNode

✔️ Global vs Local Head

• Global head is automatically initialized to NULL
• Local head must be explicitly initialized

✔️ Zero Initialization Rule

• Global/static variables are initialized to NULL (0) by default

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🔹 6. Linked List Properties

• Linear data structure
• Sequential access only
• Dynamic size (not fixed)
• Efficient insertion and deletion
• Uses pointer-based linking

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🔹 7. Array vs Linked List

Feature	Array	Linked List
Access	Random access	Sequential access
Size	Fixed	Dynamic
Memory	Contiguous	Non-contiguous
Insertion/Deletion	Costly (shifting needed)	Efficient
Memory Usage	May waste space	Allocated on demand

(Derived from comparison table in the PDF)

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⚙️ Features

• ✔️ Clear theoretical explanation
• ✔️ Node-based implementation
• ✔️ Pointer-to-pointer usage
• ✔️ Memory management concepts
• ✔️ Beginner-friendly structured notes

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🚀 Getting Started

🔧 Requirements

• C / C++ Compiler (GCC / Clang)

▶️ Run the Program

gcc program.c -o sll
./sll

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🧠 Learning Outcomes

After studying this repository, you will:

• Understand internal working of linked lists
• Learn pointer manipulation deeply
• Understand dynamic memory allocation
• Differentiate between arrays and linked lists
• Implement linked list from scratch

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📌 Future Enhancements

• Insertion & Deletion implementations
• Circular Linked List
• Doubly Linked List
• Visualization of nodes

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📜 License

This project is licensed under the MIT License.

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👨‍💻 Author

Avinandan Bose

• GitHub: @AvinandanBose

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𝑩. 𝑺𝒊𝒏𝒈𝒍𝒚 𝑳𝒊𝒏𝒌𝒆𝒅 𝑳𝒊𝒔𝒕 𝒘𝒊𝒕𝒉 𝑪𝒍𝒂𝒔𝒔 𝒊𝒏 𝑪++ 𝑫𝒂𝒕𝒂 𝑺𝒕𝒓𝒖𝒄𝒕𝒖𝒓𝒆 𝑹𝒆𝒑𝒐