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start over. Move randomly in a valid direction

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This commit is contained in:
Max Känner 2024-09-30 19:34:09 +02:00
parent d1a128e9df
commit 46f4e00e50
1 changed files with 64 additions and 98 deletions
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146
battlesnake/src/logic.rs
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@ -14,99 +14,71 @@ use log::info;
use rand::seq::SliceRandom;
use serde_json::{json, Value};
use crate::{Battlesnake, Board, Coord, Direction, Game, Move};
use crate::{Battlesnake, Board, Direction, Game, Move};
const MAX_HEALTH: i32 = 100;
impl Battlesnake {
/// Check if moving the snake in `direction` is safe.
#[must_use]
pub fn is_direction_safe(&self, direction: Direction, game: &Game, board: &Board) -> bool {
if self.is_direction_death(direction, game, board) {
return false;
}
let target = self.head.move_to(direction);
// check if a bigger snake could move to this square
if board
.snakes
.iter()
.filter(|snake| snake.id != self.id && self.length <= snake.length)
.flat_map(|snake| enum_iterator::all().map(|dir| snake.head.move_to(dir)))
.any(|coord| target == coord)
{
return false;
}
// check for hazards
if board.hazards.iter().any(|&coord| target == coord) {
return false;
}
true
}
#[must_use]
pub fn is_direction_death(&self, direction: Direction, game: &Game, board: &Board) -> bool {
let target = self.head.move_to(direction);
// check if target is out of bounds
if !((0..board.width).contains(&target.x) && (0..board.height).contains(&target.y)) {
return true;
}
// check if target is inside a snake
if board
fn possible_moves_without_heads<'a>(
&'a self,
game: &'a Game,
board: &'a Board,
) -> impl Iterator<Item = Direction> + 'a {
enum_iterator::all::<Direction>()
.filter(|direction| {
// filter out directions that would go outside the field
let target = self.head.move_to(*direction);
(0..board.width).contains(&target.x) && (0..board.height).contains(&target.y)
})
.filter(|direction| {
let target = self.head.move_to(*direction);
// don't collide with any snake
!board
.snakes
.iter()
.filter(|snake| {
!(game.ruleset.settings.squad.allow_body_collisions && self.squad == snake.squad)
// filter out snakes that are in our squad if body collisions are allowed
!(game.ruleset.settings.squad.allow_body_collisions
&& self.squad == snake.squad
&& self.id != snake.id)
})
.flat_map(|snake| {
// get all coordinates of the snake body. The tail of the body can be ignored
// if the snake hasn't just eaten, as it will move out of the way
let has_eaten = snake.health == MAX_HEALTH;
snake.body[..snake.body.len() - usize::from(!has_eaten)].iter()
})
.any(|&coord| coord == target)
})
.flat_map(|snake| snake.body.iter())
.any(|&coord| target == coord)
{
return true;
}
false
}
#[must_use]
pub fn health_cost(&self, tile: Coord, game: &Game, board: &Board) -> i32 {
// we can't leave the board
if !((0..board.width).contains(&tile.x) && (0..board.height).contains(&tile.y)) {
return self.health;
}
// we can't move into other snakes
if board
pub fn possible_moves(&self, game: &Game, board: &Board) -> Vec<Direction> {
self.possible_moves_without_heads(game, board)
.filter(|direction| {
// don't go into spots where a bigger snake must go
let target = self.head.move_to(*direction);
!board
.snakes
.iter()
.filter(|snake| {
!(game.ruleset.settings.squad.allow_body_collisions && self.squad == snake.squad)
// The other snake must be bigger than we are
snake.length > self.length
})
.flat_map(|snake| snake.body.iter())
.any(|&coord| tile == coord)
{
return self.health;
.filter_map(|snake| {
// get all snakes movement options
let moves = snake
.possible_moves_without_heads(game, board)
.collect::<Vec<_>>();
// only snakes that have a single option
match moves[..] {
[direction] => Some(snake.head.move_to(direction)),
_ => None,
}
// every step costs us one health point
let mut cost = 1;
// hazards increase the health loss
if board.hazards.iter().any(|&hazard| tile == hazard) {
cost += game.ruleset.settings.hazard_damage_per_turn;
}
// check for bigger snakes that can move into this square
for snake in board
.snakes
.iter()
.filter(|snake| snake.id != self.id && self.length <= snake.length)
{
let moves = enum_iterator::all().map(|dir| snake.head.move_to(dir));
}
cost
})
.any(|coord| coord == target)
})
.collect()
}
}
@ -139,19 +111,13 @@ 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<Move> {
let moves = enum_iterator::all()
.filter(|&direction| !you.is_direction_death(direction, game, board))
.collect::<Vec<_>>();
let safe_moves = moves
.iter()
.copied()
.filter(|&direction| you.is_direction_safe(direction, game, board))
.collect::<Vec<_>>();
let moves = you.possible_moves(game, board);
if moves.is_empty() {
return None;
}
// Choose a random move from the safe ones
let chosen = safe_moves
.choose(&mut rand::thread_rng())
.or_else(|| moves.choose(&mut rand::thread_rng()))?;
let chosen = moves.choose(&mut rand::thread_rng())?;
info!("MOVE {}: {:?}", turn, chosen);
Some(Move {