(Yet Another) Monte Carlo Tree Search

This is an implementation of Monte Carlo Tree Search (MCTS) in rust.

The features that potentially make this library a bit different from the many other MCTS libraries out there:

• Zero-dependency (all dependencies are optional)
• Pluggable RNG (default uses nanorand::WyRand)
• Multi-threaded

Usage

Add dependency

cargo add yamcts

or in the Cargo.toml file

[dependencies]
yamcts = "0.1.0"

Running MCTS

• Implement GameState
• Call run_with_duration or run_with_iterations on the game state to calculate next MCTS move
• apply_move on the game state and repeat

Example implementing Nim 21 variation

see examples/nim.rs

Run with cargo run --example nim or cargo run --release --example nim

Using a custom random number generator

The default RNG uses nanorand but if you don't want that dependency and/or would like to use a different RNG it's just necessary to implement RngProvider and Rng.

use rand::prelude::*;

// Wrapper struct, in this case rand::StdRng
struct CustomRng(StdRng);

// Implement RngProvider to return an instance of CustomRng/StdRng
impl yamcts::rng::RngProvider for CustomRng {
    fn init() -> Self {
        CustomRng(StdRng::from_entropy())
    }
}

// Implement Rng for gen_range
impl yamcts::rng::Rng for CustomRng {
    fn gen_range(&mut self, bounds: Range<usize>) -> usize {
        self.0.gen_range(bounds)
    }
}

Then to use this RNG:

let mcts = yamcts::MCTS::<CustomRng>::default();

License

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