Sudosolve

Sudosolve is a Rust crate for solving Sudoku puzzles. It takes a Sudoku puzzle as input in string format and provides the solved grid if a solution exists. The crate uses a backtracking algorithm to efficiently solve puzzles.

Features

• Parses Sudoku puzzles from a string format.
• Validates moves based on Sudoku rules.
• Solves puzzles using a recursive backtracking algorithm.
• Handles invalid or unsolvable puzzles gracefully.

Installation

You can install sudosolve directly from crates.io using Cargo:

cargo install sudosolve

Usage

Example

Here's an example of how to use the crate:

use sudosolve::SudokuBoard;

fn main() {
    let input = "53__7____6__195___98____6_8___6___34__8_3__17___2___6_6____28___419__5____8__79"; // Replace with your Sudoku string
    let mut board = SudokuBoard::new(&input);
    
    println!("Original Sudoku:");
    board.print();
    
    if board.solve() {
        println!("\nSolved Sudoku:");
        board.print();
    } else {
        println!("\nNo solution exists.");
    }
}

The input string represents the Sudoku grid, where each row is concatenated into a single string. Use _ or 0 for empty cells.

Input Format

Provide the puzzle as an 81-character string, with digits (1 to 9) for filled cells and _ or 0 for empty cells.

Rows are concatenated from left to right, top to bottom.

Example Input

53__7____
6__195___
98____6__
8___6___3
4__8_3__1
7___2___6
_6____28_
___419__5
____8__79

Should be provided as:

53__7____6__195___98____6_8___6___34__8_3__17___2___6_6____28___419__5____8__79

Development and Testing

Clone the repository and build the crate locally:

git clone https://github.com/NithinKonda/sudoku-solver.git

-> cd sudosolve

-> cargo build

-> cargo test

License

This project is licensed under the MIT License.

Contributing

Contributions are welcome! Feel free to open issues or submit pull requests on GitHub.

About the Algorithm

The solver uses a backtracking algorithm that:

1. Searches for the first empty cell.

2. Attempts to place each number (1-9) in the cell.

3. Checks the validity of the placement using Sudoku rules.

4. Recursively continues until the puzzle is solved or deemed unsolvable.

Happy solving with sudosolve!