maps_C

A Basic Hashmap (Key-Value Store) Implementation in C

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📚 Overview

maps_C is a simple and lightweight hash map (key-value store) built using C.
It supports insertion, retrieval, deletion, updating, and printing of key-value pairs with dynamic memory management. Collision handling is managed through chaining using linked lists.

Perfect for:

• Practicing C programming and pointers
• Learning how basic data structures work internally
• Exploring hashing, collisions, and memory handling

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⚙️ Features

• 🛠 Insert a key-value pair
• 🔎 Retrieve a value by key
• 🧹 Delete a key
• ✏️ Update a key’s value
• 📜 Print the entire hashmap
• 📏 Get the number of entries
• 🧹 Proper memory cleanup

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🗂️ Project Structure

maps_C/
├── LICENSE         # License file (MIT)
├── main.c          # Program with interactive menu to use the hashmap
├── map.c           # Implementation of hashmap functions
├── map.h           # Header file (definitions and function declarations)
├── Makefile        # For easy compilation
├── maps            # Compiled executable
├── README.md       # Project documentation (this file)
├── map.o           # Object file for map.c
├── main.o          # Object file for main.c

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🚀 Getting Started

Prerequisites

• GCC or any C compiler
• Basic familiarity with terminal commands

Building and Running

# Clone the repository
git clone https://github.com/Chaganti-Reddy/maps_C.git
cd maps_C

# Compile using Makefile
make

# Run the executable
./maps

Alternatively, compile manually:

gcc main.c map.c -o maps
./maps

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📖 Example Usage (Menu Options)

On running the program, you can:

1. Insert    → Add a key-value pair
2. Get       → Retrieve the value for a given key
3. Delete    → Remove a key and its value
4. Print     → Display all key-value pairs
5. Length    → Show the number of stored pairs
6. Update    → Modify the value of an existing key
7. Exit      → Free memory and exit

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🧠 Core Concepts Demonstrated

• Hashing with modulus operator
• Collision resolution with chaining (linked lists)
• Dynamic memory allocation with malloc, calloc, and free
• Modular programming in C (.h and .c separation)
• Basic CLI-based interface

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📋 Limitations

• Fixed array size (SIZE = 100), no dynamic resizing
• Only supports integer keys and integer values
• Not thread-safe (designed for single-threaded environments)

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📝 License

This project is licensed under the MIT License.

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🤝 Contributing

Feel free to open issues or submit pull requests!
Improvements, optimizations, and feature additions are very welcome.