minmax-rs

src/minmax.rs

@@ -1,82 +0,0 @@
-use std::time::Instant;
-
-use crate::{Game, GamePlayer, Player, Score, State};
-
-#[derive(Clone)]
-pub struct PerfectPlayer<G: Game> {
-    best_move: Option<G::Move>,
-    max_depth: Option<usize>,
-    print_time: bool,
-}
-
-impl<G: Game> Default for PerfectPlayer<G> {
-    fn default() -> Self {
-        Self::new(true)
-    }
-}
-
-impl<G: Game> PerfectPlayer<G> {
-    pub fn new(print_time: bool) -> Self {
-        Self {
-            best_move: None,
-            max_depth: G::REASONABLE_SEARCH_DEPTH,
-            print_time,
-        }
-    }
-
-    pub fn with_max_depth(mut self, max_depth: Option<usize>) -> Self {
-        self.max_depth = max_depth;
-        self
-    }
-
-    fn minmax(&mut self, board: &mut G, player: Player, depth: usize) -> Score {
-        if let Some(max_depth) = self.max_depth && depth >= max_depth {
-            return board.rate(player);
-        }
-
-        match board.result() {
-            State::Winner(winner) => {
-                if winner == player {
-                    Score::WON
-                } else {
-                    Score::LOST
-                }
-            }
-            State::Draw => Score::TIE,
-            State::InProgress => {
-                let mut max_value = Score::MIN;
-
-                for pos in board.possible_moves() {
-                    board.make_move(pos, player);
-                    let value = -self.minmax(board, player.opponent(), depth + 1);
-
-                    board.undo_move(pos);
-
-                    if value > max_value {
-                        max_value = value;
-                        if depth == 0 {
-                            self.best_move = Some(pos);
-                        }
-                    }
-                }
-
-                max_value
-            }
-        }
-    }
-}
-
-impl<G: Game> GamePlayer<G> for PerfectPlayer<G> {
-    fn next_move(&mut self, board: &mut G, this_player: Player) {
-        let start = Instant::now();
-        self.best_move = None;
-        self.minmax(board, this_player, 0);
-
-        board.make_move(self.best_move.expect("could not make move"), this_player);
-
-        if self.print_time {
-            let duration = start.elapsed();
-            println!("Move took {duration:?}");
-        }
-    }
-}