Expand description
A 2048 implementation that uses bit-shifting and a pre-computed move table this implementation is designed to provide low overhead when testing an algorithm on a large amount of games. On a mid-2015 MBP Retina (2.5GHz i7) 10,000,000 games take about 80 seconds to complete running on 8 threads (1,250,000 games per thread) by executing random moves, avg score ~2k.
The board itself is encoded as a u64
. This means that each tile has 4 bits (64 / 16 = 4) to store its
value. Since the maximum value of setting all four bits to 1 is 15
we cannot use it to
display the value directly. Instead we use these 4 bits as the power value: 2 << 15 = 65536
, 2 << 14 = 32768
, 2 << 13 = 16384
, 2 << 12 = 8192
, etc…
A simple way to play the game automatically is to use tfe::Game::play
:
extern crate tfe;
use tfe::{Game, Direction};
let game = Game::play(|board, failed| Direction::sample_without(failed));
println!("score: {:<6} board hex: {:016x}", Game::score(game.board), game.board);
The play
method takes a closure that accepts a board: u64
and failed: &Vec<Direction>
as
parameters and returns a Direction
to move in.
The game will terminate automatically if each distinct move has been attempted and failed without any successfull move in between the failed moves.
references:
- https://github.com/nneonneo/2048-ai/blob/master/2048.h
- https://github.com/nneonneo/2048-ai/blob/master/2048.cpp
- https://stackoverflow.com/questions/22342854/what-is-the-optimal-algorithm-for-the-game-2048
Structs§
- Game
- Struct used to play a single game of 2048.
Enums§
- Direction
- Enum that stores all available directions. This enum also provides some basic functions to allow a game to be using random moves.