Sudoku (Rust Engine + TUI + WASM + iOS)

Shared Sudoku engine written in Rust, with:

• Core engine (sudoku-core)
• Terminal UI (crates/sudoku-tui)
• WebAssembly build (crates/sudoku-wasm)
• iOS app via UniFFI (crates/sudoku-ffi + ios/)

App Store: https://apps.apple.com/us/app/sudoku/id6758485043

Brand page (GitHub Pages): https://kcirtapfromspace.github.io/sudoku/

Demos

TUI

WASM

Quickstart

TUI

cargo run -p sudoku-tui --bin sudoku

WASM

wasm-pack build crates/sudoku-wasm --target web --out-dir crates/sudoku-wasm/www/pkg --release
cd crates/sudoku-wasm/www
python3 serve.py 8080

Then open http://127.0.0.1:8080/.

Live at ukodus.now/play.

iOS

Open ios/Sudoku/Sudoku.xcodeproj in Xcode and run the Sudoku scheme.

Puzzle Generation (Rust)

Puzzle generation lives in the Rust core crate:

• Generator: generator.rs
• Solver + uniqueness + difficulty rating: src/solver/ (modular directory with engines for fish, ALS, AIC, uniqueness, etc.)

At a high level:

1. Create a fully solved grid (a complete valid Sudoku solution).
2. Remove givens while preserving uniqueness:
   • Remove values (using symmetric pairs) to form a puzzle.
   • After each removal, verify the puzzle still has exactly one solution (the solver stops once it finds 2).
3. Rate the puzzle difficulty using a human-style technique simulation and retry generation until it matches the requested difficulty.

The PuzzleId system (puzzle_id.rs) encodes puzzle parameters into short alphanumeric codes, enabling deterministic regeneration and shareable puzzle links.

The iOS app uses this same generator through the Rust FFI layer (crates/sudoku-ffi), and stores the solved grid alongside the puzzle so it can power hints and validation. The WASM build powers ukodus.now/play and includes an anti-cheat move log that records timestamped actions for leaderboard verification.