logical improvements

src/complexagent.rs

@@ -183,24 +183,23 @@ impl FutureMoves {
     }
 
     fn compute_values(&mut self) {
-        // PERF! doing this filtering here previously visited moves reduces time
-        // spent in `depth_of` from 27.79% -> 2.9%
-        let mut visited = vec![false; self.arena.len()];
-
-        for depth in (0..=self.current_depth).rev() {
-            for (idx, was_visited) in visited.iter_mut().enumerate() {
-                if *was_visited {
-                    continue;
-                } else {
-                    *was_visited = true;
+        // PERF! pre-organize all indexes based on what depth they're at
+        // previously, I did a lookup map based on if a node was visited, still resulted in a full
+        // O(n) iteration each depth
+        let mut by_depth: Vec<Vec<usize>> = (0..=self.max_depth + 2).map(|_| Vec::new()).collect();
+        for idx in 0..self.arena.len() {
+            let depth = self.depth_of(idx);
+            // -1 because `depth_of` is zero-indexed
+            by_depth[depth - 1].push(idx);
         }
 
-                if self.depth_of(idx) != depth as usize {
-                    continue;
-                }
+        for (depth, nodes) in by_depth.into_iter().enumerate().rev() {
+            // because enum is 0-index, inc depth
+            let depth = depth + 1;
 
-                let self_value = self.arena[idx].compute_self_value(self.agent_color)
-                    / (self.current_depth - depth + 1) as i64;
+            for idx in nodes {
+                let self_value =
+                    self.arena[idx].compute_self_value(self.agent_color) / (depth as isize) as i64;
 
                 let children_value = self.arena[idx]
                     .children
@@ -263,6 +262,9 @@ impl FutureMoves {
         }
     }
 
+    /// Update the root based on the coordinate of the move
+    /// Returns a boolean, `true` if the operation was successful, false if not
+    #[must_use = "You must check if the root was properly set"]
     pub fn update_root_coord(&mut self, i: usize, j: usize) -> bool {
         self.arena
             .iter()
@@ -317,6 +319,9 @@ impl FutureMoves {
                 if let Some(parent) = node.parent.as_mut() {
                     if let Some(new_parent) = index_map[*parent] {
                         *parent = new_parent;
+                    } else {
+                        // make sure we don't have dangling parents
+                        node.parent = None;
                     }
                 }
 
@@ -344,7 +349,7 @@ pub struct ComplexAgent {
 
 impl ComplexAgent {
     pub const fn new(color: Piece) -> Self {
-        const MAX_DEPTH: usize = 15;
+        const MAX_DEPTH: usize = 17;
         Self {
             color,
             future_moves: FutureMoves::new(color, MAX_DEPTH),