feat: Killer move 表 — 2-slot/depth + 3 测试

core/src/ai/killer.rs

@@ -0,0 +1,72 @@
+use crate::types::Position;
+
+const MAX_DEPTH: usize = 32;
+const SLOTS_PER_DEPTH: usize = 2;
+
+pub struct KillerTable {
+    moves: [[Option<Position>; SLOTS_PER_DEPTH]; MAX_DEPTH],
+}
+
+impl KillerTable {
+    pub fn new() -> Self {
+        Self {
+            moves: [[None; SLOTS_PER_DEPTH]; MAX_DEPTH],
+        }
+    }
+
+    /// 记录产生剪枝的走法，同一位置不会重复存储
+    pub fn record(&mut self, depth: usize, pos: Position) {
+        if depth >= MAX_DEPTH {
+            return;
+        }
+        let slot0 = self.moves[depth][0];
+        if slot0 != Some(pos) {
+            self.moves[depth][1] = slot0;
+            self.moves[depth][0] = Some(pos);
+        }
+    }
+
+    /// 获取该深度的 killer moves（优先级: slot0 > slot1）
+    pub fn get(&self, depth: usize) -> [Option<Position>; SLOTS_PER_DEPTH] {
+        if depth >= MAX_DEPTH {
+            return [None, None];
+        }
+        self.moves[depth]
+    }
+
+    pub fn clear(&mut self) {
+        self.moves = [[None; SLOTS_PER_DEPTH]; MAX_DEPTH];
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_record_and_get() {
+        let mut kt = KillerTable::new();
+        kt.record(3, Position::new(7, 7));
+        assert_eq!(kt.get(3)[0], Some(Position::new(7, 7)));
+    }
+
+    #[test]
+    fn test_two_slots_eviction() {
+        let mut kt = KillerTable::new();
+        kt.record(1, Position::new(7, 7));
+        kt.record(1, Position::new(8, 8));
+        kt.record(1, Position::new(9, 9));
+        let got = kt.get(1);
+        assert_eq!(got[0], Some(Position::new(9, 9)));
+        assert_eq!(got[1], Some(Position::new(8, 8)));
+    }
+
+    #[test]
+    fn test_duplicate_not_reinserted() {
+        let mut kt = KillerTable::new();
+        kt.record(2, Position::new(7, 7));
+        kt.record(2, Position::new(7, 7));
+        assert_eq!(kt.get(2)[0], Some(Position::new(7, 7)));
+        assert_eq!(kt.get(2)[1], None);
+    }
+}

core/src/ai/mod.rs

@@ -8,4 +8,5 @@ pub trait AiEngine: Send + Sync {
 }
 
 pub mod evaluate;
+pub mod killer;
 pub mod search;