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compare: max:7eb6eff65abdb3dd15fc342b4768837af35aa678
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4 changed files with 11 additions and 326 deletions
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72
battlesnake/src/logic.rs
View File

@ -10,12 +10,11 @@
// To get you started we've included code to prevent your Battlesnake from moving backwards.
// For more info see docs.battlesnake.com
use std::{cmp::Ordering, time::Instant};
use log::info;
use rand::seq::SliceRandom;
use serde_json::{json, Value};
use crate::{simulation, Action, Battlesnake, Board, Direction, Game, MAX_HEALTH};
use crate::{Action, Battlesnake, Board, Direction, Game, MAX_HEALTH};
impl Battlesnake {
fn possible_actions_without_heads<'a>(
@ -110,72 +109,17 @@ pub fn end(_game: &Game, _turn: i32, _board: &Board, _you: &Battlesnake) {
// Valid moves are "up", "down", "left", or "right"
// See https://docs.battlesnake.com/api/example-move for available data
pub fn get_move(game: &Game, turn: i32, board: &Board, you: &Battlesnake) -> Option<Action> {
let id_map = board
.snakes
.iter()
.enumerate()
.map(|(i, snake)| (snake.id.clone(), u8::try_from(i).unwrap()))
.collect();
let board = simulation::Board::from_game_board(board, &id_map, turn);
let my_id = id_map[&you.id];
let my_index = board.snake_index(my_id)?;
let possible_actions = board.possible_actions();
let my_actions = &possible_actions[my_index];
let actions = my_actions
.iter()
.map(|direction| {
let mut actions = vec![None; possible_actions.len()];
actions[my_index] = Some(*direction);
let mut wins = 0;
let mut total_turns = 0;
let start = Instant::now();
for _ in 0..100 {
let mut board = board.clone();
board.simulate_with_initial_until(&actions[..], |board| {
!board.is_alive(my_id)
|| (game.ruleset.name != "solo" && board.alive_snakes() <= 1)
});
if board.is_alive(my_id) {
// we survived
wins += 2;
} else if board.alive_snakes() == 0 {
// no snake is alive. This is a draw
wins += 1;
} else {
// we lost
wins += 0;
let actions = you.possible_actions(game, board);
if actions.is_empty() {
return None;
}
total_turns += board.turn();
}
let end = Instant::now();
info!(
"Simulation for {direction:?} took {}s",
(end - start).as_secs_f32()
);
(direction, wins, total_turns)
})
.collect::<Vec<_>>();
info!("actions: {actions:?}");
let (&chosen, _, _) =
actions
.into_iter()
.max_by(
|(_, score1, turns1), (_, score2, turns2)| match score1.cmp(score2) {
Ordering::Equal => turns1.cmp(turns2),
order => order,
},
)?;
// Choose a random move from the safe ones
let chosen = actions.choose(&mut rand::thread_rng())?;
info!("DIRECTION {}: {:?}", turn, chosen);
Some(Action {
r#move: chosen,
r#move: *chosen,
shout: None,
})
}

5
battlesnake/src/main.rs
View File

@ -11,7 +11,6 @@ use serde_json::Value;
use std::env;
mod logic;
mod simulation;
const MAX_HEALTH: i32 = 100;
@ -120,7 +119,7 @@ pub struct RulesetSquad {
shared_length: bool,
}
#[derive(Deserialize, Serialize, Debug, Clone)]
#[derive(Deserialize, Serialize, Debug)]
pub struct Board {
/// The number of rows in the y-axis of the game board.
height: i32,
@ -135,7 +134,7 @@ pub struct Board {
hazards: Vec<Coord>,
}
#[derive(Deserialize, Serialize, Debug, Clone)]
#[derive(Deserialize, Serialize, Debug)]
pub struct Battlesnake {
/// Unique identifier for this Battlesnake in the context of the current Game
id: String,

257
battlesnake/src/simulation.rs
View File

@ -1,257 +0,0 @@
use std::collections::{BTreeSet, HashMap, VecDeque};
use rand::seq::SliceRandom;
use crate::{Coord, Direction};
const MAX_HEALTH: u8 = crate::MAX_HEALTH as u8;
#[derive(Debug, PartialEq, Eq, Clone)]
pub struct Board {
turn: i32,
/// Height of the board
height: i32,
/// Width of the board
width: i32,
/// Food on the board
food: BTreeSet<Coord>,
/// Alive snakes
snakes: Vec<Battlesnake>,
}
impl Board {
pub fn from_game_board(board: &crate::Board, id_map: &HashMap<String, u8>, turn: i32) -> Self {
let width = board.width;
debug_assert!(width > 0);
let height = board.height;
debug_assert!(height > 0);
let food = board.food.iter().copied().collect();
let snakes = board
.snakes
.iter()
.map(|snake| {
let id = id_map[&snake.id];
Battlesnake::from_game_snake(snake, id)
})
.collect();
Self {
turn,
height,
width,
food,
snakes,
}
}
pub const fn turn(&self) -> i32 {
self.turn
}
pub fn snake_index(&self, id: u8) -> Option<usize> {
self.snakes
.iter()
.enumerate()
.find(|(_, snake)| snake.id == id)
.map(|(i, _)| i)
}
pub fn is_alive(&self, id: u8) -> bool {
self.snakes.iter().any(|snake| snake.id == id)
}
pub fn alive_snakes(&self) -> usize {
self.snakes.len()
}
pub fn simulate_actions(&mut self, actions: &[Direction]) {
debug_assert_eq!(self.snakes.len(), actions.len());
// move snakes
for (snake, direction) in self.snakes.iter_mut().zip(actions.iter()) {
snake.perform_action(*direction);
}
// feed snakes
for snake in &mut self.snakes {
let head = snake.head();
if self.food.remove(head) {
snake.health = MAX_HEALTH;
}
}
// kill snakes
let alive_ids = self
.snakes
.iter()
.filter(|snake| {
// snake must have enough health
snake.health != 0
})
.map(|snake| (snake.id, snake.body.len(), *snake.head()))
.filter(|(_, _, head)| {
// head in bounds
(0..self.width).contains(&head.x) && (0..self.height).contains(&head.y)
})
.filter(|(_, _, head)| {
// body collision
!self
.snakes
.iter()
.flat_map(|snake2| snake2.body.iter().skip(1))
.any(|body| body == head)
})
.filter(|(id, len, head)| {
// head to head collision
!self
.snakes
.iter()
.filter(|snake2| snake2.id != *id && snake2.body.len() >= *len)
.any(|snake2| snake2.head() == head)
})
.map(|(id, _, _)| id)
.collect::<Vec<_>>();
self.snakes.retain(|snake| alive_ids.contains(&snake.id));
self.turn += 1;
}
pub fn simulate_with_initial_until(
&mut self,
actions: &[Option<Direction>],
exit: impl Fn(&Self) -> bool,
) {
debug_assert_eq!(actions.len(), self.snakes.len());
let possible_actions = self.possible_actions();
let actions = actions
.iter()
.enumerate()
.map(|(i, direction)| {
direction.unwrap_or_else(|| {
possible_actions[i]
.choose(&mut rand::thread_rng())
.copied()
.unwrap_or(Direction::Up)
})
})
.collect::<Vec<_>>();
self.simulate_actions(&actions);
while !exit(self) {
let actions = self
.possible_actions()
.iter()
.map(|actions| {
actions
.choose(&mut rand::thread_rng())
.copied()
.unwrap_or(Direction::Up)
})
.collect::<Vec<_>>();
self.simulate_actions(&actions);
}
}
pub fn possible_actions(&self) -> Vec<Vec<Direction>> {
let possible_actions = self
.snakes
.iter()
.map(|snake| {
enum_iterator::all::<Direction>()
.map(|direction| (direction, snake.head().move_to(direction)))
.filter(|(_, target)| {
// don't move out of bounds
(0..self.width).contains(&target.x) && (0..self.height).contains(&target.y)
})
.filter(|(_, target)| {
// don't collide with other snakes
!self
.snakes
.iter()
.flat_map(|snake| {
let has_eaten = snake.health == MAX_HEALTH;
snake
.body
.iter()
.take(snake.body.len() - usize::from(!has_eaten))
})
.any(|coord| coord == target)
})
.map(|(direction, _)| direction)
.collect::<Vec<_>>()
})
.collect::<Vec<_>>();
// don't move into bigger snakes heads with only one movement option
possible_actions
.iter()
.enumerate()
.map(|(i, actions)| {
let snake = &self.snakes[i];
let length = snake.body.len();
let head = snake.head();
actions
.iter()
.copied()
.filter(|direction| {
let target = head.move_to(*direction);
!self
.snakes
.iter()
.enumerate()
.filter(|(_, snake)| {
// only snakes that are longer
snake.body.len() > length
})
.filter_map(|(i, snake)| match &possible_actions[i][..] {
// only snakes that have a single action option
[direction] => Some(snake.head().move_to(*direction)),
_ => None,
})
.any(|coord| coord == target)
})
.collect()
})
.collect()
}
}
#[derive(Debug, PartialEq, Eq, Clone)]
pub struct Battlesnake {
/// Id of the snake. Unique inside a game
id: u8,
/// health points
health: u8,
/// Body of the snake. The head is the first element in the queue
body: VecDeque<Coord>,
}
impl Battlesnake {
pub fn from_game_snake(snake: &crate::Battlesnake, id: u8) -> Self {
let body: VecDeque<_> = snake.body.iter().copied().collect();
debug_assert_eq!(body.len(), usize::try_from(snake.length).unwrap());
debug_assert!(snake.health <= crate::MAX_HEALTH);
let health = u8::try_from(snake.health).expect("max health is 100");
Self { id, health, body }
}
pub fn perform_action(&mut self, direction: Direction) {
debug_assert!(!self.body.is_empty());
// move the head along
self.body.push_front(self.head().move_to(direction));
// move tail
if self.health != MAX_HEALTH {
// only move the tail if we didn't eat
self.body.pop_back();
}
// decrease helth
self.health = self.health.saturating_sub(1);
}
pub fn head(&self) -> &Coord {
debug_assert!(!self.body.is_empty());
self.body.front().expect("not empty")
}
}

1
xtask/src/main.rs
View File

@ -120,7 +120,6 @@ fn vs_production() -> Result<(), DynError> {
"https://snake.mkaenner.de",
"-g",
"duel",
"--browser",
])
.output();