Sudoku Solver 🧩

A Sudoku solver implemented with Rust.

---

📖 Table of Contents

• Overview
• Features
• Motivation
• Installation
• Usage
  • Building
  • Running
• Examples
• Testing
• Roadmap
• Contributing
• Acknowledgements
• License

---

🔍 Overview

This repository provides a command-line Sudoku solver algorithm written in Rust.
It takes a partially filled Sudoku board and attempts to solve it, yielding a completed board if the puzzle is valid and solvable.

---

✨ Features

• Pure Rust implementation
• Efficient backtracking / search-based solver
• Clean and minimal dependencies
• Unit-tested logic
• Simple CLI for running puzzles

---

🎯 Motivation

The project was built to:

• Explore algorithmic problem solving in Rust
• Practice ownership, borrowing, and efficient data structures
• Provide a simple tool for solving Sudoku puzzles

---

⚙️ Installation

Make sure you have Rust installed (via rustup).

Clone the repo:

git clone https://github.com/jplotkin05/sudoku-solver.git
cd sudoku-solver

---

🚀 Usage

Building

Build the project in release mode for best performance:

cargo build --release

Running

Run the solver with a Sudoku input file:

cargo run -- puzzles/example.txt

• Input must be a text file with the Sudoku grid written row by row.
• Use . or 0 to represent blank cells.
• The solver will print the solved board (or report if unsolvable).

---

🖼 Examples

Example Input (puzzles/example.txt):

5 3 . . 7 . . . .
6 . . 1 9 5 . . .
. 9 8 . . . . 6 .
8 . . . 6 . . . 3
4 . . 8 . 3 . . 1
7 . . . 2 . . . 6
. 6 . . . . 2 8 .
. . . 4 1 9 . . 5
. . . . 8 . . 7 9

Example Run:

cargo run -- puzzles/example.txt

Example Output:

5 3 4 6 7 8 9 1 2
6 7 2 1 9 5 3 4 8
1 9 8 3 4 2 5 6 7
8 5 9 7 6 1 4 2 3
4 2 6 8 5 3 7 9 1
7 1 3 9 2 4 8 5 6
9 6 1 5 3 7 2 8 4
2 8 7 4 1 9 6 3 5
3 4 5 2 8 6 1 7 9

---

✅ Testing

Run the unit tests:

cargo test

---

🛤 Roadmap

• Add difficulty classification (easy, medium, hard)
• Benchmark performance on large sets of puzzles
• Support for multiple solution strategies
• Option to generate Sudoku puzzles

---

🤝 Contributing

Contributions are welcome!

1. Fork the repo
2. Create your feature branch (git checkout -b feature/my-feature)
3. Commit your changes (git commit -m 'Add some feature')
4. Push to the branch (git push origin feature/my-feature)
5. Open a pull request

---

🙏 Acknowledgements

• Rust for making systems programming fun and safe
• Classic Sudoku puzzle inspiration

---

📄 License

This project is licensed under the MIT License.
See the LICENSE file for details.