Data Structures and Algorithms Notes for Kotlin

A comprehensive collection of data structures and algorithms implementations and solutions written in Kotlin. This repository contains solutions to coding interview problems from various platforms including LeetCode and HackerRank, organized by topic and difficulty.

📖 Project Overview

This project serves as a learning resource and reference guide for data structures and algorithms concepts using Kotlin. It includes:

• Algorithm implementations with detailed explanations
• Coding interview problem solutions from popular platforms
• Educational notes and documentation for key concepts
• Well-organized structure by topic and problem source

🏗️ Project Structure

src/main/kotlin/
├── Main.kt                     # Application entry point
├── array/                      # Array data structure and algorithms
│   ├── ARRAY.md               # Comprehensive array concepts guide
│   └── leetcode/              # LeetCode array problems
├── hackerrank/                # HackerRank problem solutions
│   ├── arrays/                # Array problems
│   ├── dictionariesandhashmaps/ # Hash table problems
│   ├── gettingstarted/        # Beginner problems
│   ├── sorting/               # Sorting algorithms
│   ├── stringmanipulation/    # String problems
│   └── warmup/                # Warm-up problems
└── leetcode/                  # LeetCode problem solutions
    ├── arrays/                # Array problems
    ├── hashmapset/            # HashMap and HashSet problems
    ├── prefixsum/             # Prefix sum technique
    ├── slidingwindow/         # Sliding window technique
    └── twopointers/           # Two pointers technique

🎯 Topics Covered

Data Structures

• Arrays - Operations, techniques, and common patterns
• Hash Tables - HashMaps, HashSets, and applications
• Strings - Manipulation and pattern matching

Algorithms & Techniques

• Sorting - Various sorting algorithms and applications
• Two Pointers - Efficient array/string traversal
• Sliding Window - Subarray/substring optimization
• Prefix Sum - Efficient range sum queries
• Binary Search - Search in sorted arrays

Problem Sources

• LeetCode - Popular coding interview problems
• HackerRank - Programming challenges and contests

🚀 Getting Started

Prerequisites

• JDK 8 or higher
• Gradle (included via Gradle Wrapper)

Setup

1. Clone the repository:

   git clone https://github.com/erenalpaslan/data-structures-and-algorithm-kotlin.git
   cd data-structures-and-algorithm-kotlin

2. Build the project:

   ./gradlew build

3. Run the application:

   ./gradlew run

Running Tests

./gradlew test

📚 Learning Resources

Each topic includes:

• Theoretical explanations with time/space complexity analysis
• Code implementations with detailed comments
• Example problems and their solutions
• Common patterns and techniques

For detailed array concepts and techniques, see ARRAY.md.

🛠️ Technologies Used

• Kotlin 1.9.24 - Primary programming language
• Gradle - Build automation and dependency management
• JUnit - Unit testing framework

🤝 Contributing

Contributions are welcome! Please feel free to submit pull requests or open issues for:

• Bug fixes
• New algorithm implementations
• Additional problem solutions
• Documentation improvements

📝 Notes

This project is designed for educational purposes and coding interview preparation. Each solution includes:

• Time and space complexity analysis
• Multiple approaches where applicable
• Edge case handling
• Clean, readable code with comments

📄 License

This project is open source and available under the MIT License.

---

Happy Coding! 🎉