Add initial Amazons implementation

Author: t4ccer

src/grid.rs

@@ -149,7 +149,7 @@ fn bfs<G, T>(
     y: u8,
     is_non_blocking: fn(T) -> bool,
     blocking_tile: T,
-    directions: &[(i64, i64)],
+    directions: &[(i32, i32)],
 ) -> G
 where
     T: Copy + Default,
@@ -166,13 +166,13 @@ where
         new_grid.set(qx, qy, grid.get(qx, qy));
 
         for (dx, dy) in directions {
-            let lx = (qx as i64) + dx;
-            let ly = (qy as i64) + dy;
+            let lx = (qx as i32) + dx;
+            let ly = (qy as i32) + dy;
 
             if lx >= 0
-                && lx < (grid.width() as i64)
+                && lx < (grid.width() as i32)
                 && ly >= 0
-                && ly < (grid.height() as i64)
+                && ly < (grid.height() as i32)
                 && is_non_blocking(grid.get(lx as u8, ly as u8))
                 && is_non_blocking(visited.get(lx as u8, ly as u8))
             {
@@ -189,7 +189,7 @@ pub fn decompositions<G, T>(
     grid: &G,
     is_non_blocking: fn(T) -> bool,
     blocking_tile: T,
-    directions: &[(i64, i64)],
+    directions: &[(i32, i32)],
 ) -> Vec<G>
 where
     T: Copy + Default,

src/short/partizan/games.rs

@@ -1,5 +1,6 @@
 //! Partizan games under normal play i.e. the player that cannot move in their turn loses.
 
+pub mod amazons;
 pub mod domineering;
 pub mod fission;
 pub mod ski_jumps;

src/short/partizan/games/amazons.rs

@@ -0,0 +1,192 @@
+//! Amazons game
+
+use crate::{
+    grid::{decompositions, move_top_left, vec_grid::VecGrid, FiniteGrid, Grid},
+    short::partizan::partizan_game::PartizanGame,
+};
+use cgt_derive::Tile;
+use std::{fmt::Display, hash::Hash, str::FromStr};
+
+/// Tile in the game of Amazons
+#[derive(Debug, Hash, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Tile)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
+pub enum Tile {
+    /// Empty tile without stones
+    #[tile(char('.'), default)]
+    Empty,
+
+    /// Tile with Left player's Amazon - black queen
+    #[tile(char('x'))]
+    Left,
+
+    /// Tile with Right player's Amazon - white queen
+    #[tile(char('o'))]
+    Right,
+
+    /// Stone
+    #[tile(char('#'))]
+    Stone,
+}
+
+impl Tile {
+    #[inline]
+    fn is_non_blocking(self: Tile) -> bool {
+        self != Tile::Stone
+    }
+}
+
+/// Game of Amazons
+#[derive(Debug, Hash, Clone, PartialEq, Eq, PartialOrd, Ord)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
+pub struct Amazons<G = VecGrid<Tile>> {
+    grid: G,
+}
+
+impl<G> Display for Amazons<G>
+where
+    G: Grid<Item = Tile> + FiniteGrid,
+{
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        self.grid.display(f, '|')
+    }
+}
+
+impl<G> FromStr for Amazons<G>
+where
+    G: Grid<Item = Tile> + FiniteGrid,
+{
+    type Err = ();
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        Ok(Self::new(G::parse(s).ok_or(())?))
+    }
+}
+
+const DIRECTIONS: [(i32, i32); 8] = [
+    (-1, 0),
+    (-1, 1),
+    (0, 1),
+    (1, 1),
+    (1, 0),
+    (1, -1),
+    (0, -1),
+    (-1, -1),
+];
+
+impl<G> Amazons<G>
+where
+    G: Grid<Item = Tile> + FiniteGrid,
+{
+    /// Create new Amazons game from a grid
+    #[inline]
+    pub fn new(grid: G) -> Self {
+        Amazons { grid }
+    }
+
+    fn moves_for(&self, own_amazon: Tile) -> Vec<Self>
+    where
+        G: Clone + PartialEq,
+    {
+        let longer_side = self.grid.height().max(self.grid.width());
+
+        let mut moves = Vec::new();
+        for y in 0..self.grid.height() as i32 {
+            for x in 0..self.grid.width() as i32 {
+                if self.grid.get(x as u8, y as u8) == own_amazon {
+                    for (amazon_dir_x, amazon_dir_y) in DIRECTIONS {
+                        for k in 1..longer_side as i32 {
+                            let new_amazon_x = x + amazon_dir_x * k;
+                            let new_amazon_y = y + amazon_dir_y * k;
+
+                            if new_amazon_x < 0
+                                || new_amazon_x >= self.grid.width() as i32
+                                || new_amazon_y < 0
+                                || new_amazon_y >= self.grid.height() as i32
+                                || self.grid.get(new_amazon_x as u8, new_amazon_y as u8)
+                                    != Tile::Empty
+                            {
+                                break;
+                            }
+                            let mut new_grid = self.grid.clone();
+                            new_grid.set(x as u8, y as u8, Tile::Empty);
+                            new_grid.set(new_amazon_x as u8, new_amazon_y as u8, own_amazon);
+                            for (arrow_dir_x, arrow_dir_y) in DIRECTIONS {
+                                for l in 1..longer_side as i32 {
+                                    let new_arrow_x = new_amazon_x + arrow_dir_x * l;
+                                    let new_arrow_y = new_amazon_y + arrow_dir_y * l;
+
+                                    if new_arrow_x < 0
+                                        || new_arrow_x >= new_grid.width() as i32
+                                        || new_arrow_y < 0
+                                        || new_arrow_y >= new_grid.height() as i32
+                                        || new_grid.get(new_arrow_x as u8, new_arrow_y as u8)
+                                            != Tile::Empty
+                                    {
+                                        break;
+                                    }
+                                    let mut new_grid = new_grid.clone();
+                                    new_grid.set(new_arrow_x as u8, new_arrow_y as u8, Tile::Stone);
+                                    let new_grid = move_top_left(&new_grid, Tile::is_non_blocking);
+                                    moves.push(Self::new(new_grid));
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+        }
+
+        moves
+    }
+}
+
+impl<G> PartizanGame for Amazons<G>
+where
+    G: Grid<Item = Tile> + FiniteGrid + Clone + Hash + Send + Sync + Eq,
+{
+    fn left_moves(&self) -> Vec<Self> {
+        self.moves_for(Tile::Left)
+    }
+
+    fn right_moves(&self) -> Vec<Self> {
+        self.moves_for(Tile::Right)
+    }
+
+    fn decompositions(&self) -> Vec<Self> {
+        decompositions(&self.grid, Tile::is_non_blocking, Tile::Stone, &DIRECTIONS)
+            .into_iter()
+            .map(Self::new)
+            .collect::<Vec<_>>()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::short::partizan::{
+        canonical_form::CanonicalForm, transposition_table::TranspositionTable,
+    };
+    use std::str::FromStr;
+
+    macro_rules! amazons {
+        ($input:expr) => {
+            Amazons::from_str($input).expect("Could not parse the game")
+        };
+    }
+
+    macro_rules! test_canonical_form {
+        ($input:expr, $output:expr) => {{
+            let tt = TranspositionTable::new();
+            let pos: Amazons = amazons!($input);
+            let cf = pos.canonical_form(&tt);
+            let expected = CanonicalForm::from_str($output).unwrap().to_string();
+            assert_eq!(cf.to_string(), expected);
+        }};
+    }
+
+    #[test]
+    fn canonical_form() {
+        // Confirmed with cgsuite
+        test_canonical_form!("x..#|....|.#.o", "{{6|{3|1, {3|0, {1/2|0}}}}, {6|{4*|-3, {3, {3|0, {1/2|0}}|-4}}}|-3, {0, {0|-2}, {1|-3}|-5}, {0, {0, *|0, {0, {1/2, {1|0}|v}|v}}|-5}, {{2, {2|0}|0, {0, {2|0, {2|0}}|0}}, {2, {3|0}|0, {0, {0, ^*|0}|-1}}, {{2|0}, {2|{1|1/4}, {2|0}}|v*, {1/2|{{0|-1}, {*|-1}|-1}}, {{0, ^*|0}|-1}}, {{3|0}, {3|1, {2|0}}, {3, {3|1}|1, {1|0, *}}|-1/16, {0|-1}, {*|-1}}|-5, {v, v*, {0, {0, ^*|0}|-1}|-5}, {{1/2|{-1/4, {0|-1}, {*|-1}|-1}}, {{1|1/4}|{-1/4|-1}}, {{1|{1|0}, {1|*}}|-1/2}|-5}}}");
+    }
+}

src/short/partizan/games/fission.rs

@@ -88,11 +88,11 @@ where
                     && self.grid.get(prev_x, prev_y) == Tile::Empty
                     && self.grid.get(next_x, next_y) == Tile::Empty
                 {
-                    let mut new_grid: Self = self.clone();
-                    new_grid.grid.set(x, y, Tile::Empty);
-                    new_grid.grid.set(prev_x, prev_y, Tile::Stone);
-                    new_grid.grid.set(next_x, next_y, Tile::Stone);
-                    moves.push(new_grid);
+                    let mut new_grid = self.clone().grid;
+                    new_grid.set(x, y, Tile::Empty);
+                    new_grid.set(prev_x, prev_y, Tile::Stone);
+                    new_grid.set(next_x, next_y, Tile::Stone);
+                    moves.push(Self::new(new_grid));
                 }
             }
         }