From 9ffc6ecd016fc72b46949a8338ae26ed2f0bb074 Mon Sep 17 00:00:00 2001
From: Simon Gardling <titaniumtown@proton.me>
Date: Sat, 15 Feb 2025 23:31:18 -0500
Subject: [PATCH] prune agent move tree (8->17 depth)

---
 src/complexagent.rs | 32 +++++++++++++++++++++++---------
 1 file changed, 23 insertions(+), 9 deletions(-)

diff --git a/src/complexagent.rs b/src/complexagent.rs
index 15f7fa4..71f082d 100644
--- a/src/complexagent.rs
+++ b/src/complexagent.rs
@@ -30,7 +30,7 @@ struct Move {
 
 impl Move {
     fn compute_self_value(&self, agent_color: Piece, depth: usize) -> i64 {
-        let mut self_value = self.board.count(agent_color) as i64;
+        let mut self_value = self.value;
 
         if self.winner == Some(!agent_color) {
             // if this board results in the opponent winning, MAJORLY negatively weigh this move
@@ -100,6 +100,14 @@ impl FutureMoves {
             let arena_len = self.arena.len();
             next_nodes = next_nodes
                 .into_iter()
+                .progress_with(
+                    ProgressBar::new(arena_len as u64).with_style(
+                        ProgressStyle::with_template(
+                            "Generating children: ({pos}/{len}) {per_sec}",
+                        )
+                        .unwrap(),
+                    ),
+                )
                 .flat_map(|node_idx| {
                     self.generate_children(
                         Some(node_idx),
@@ -107,9 +115,6 @@ impl FutureMoves {
                         next_color,
                     )
                 })
-                .progress_with(ProgressBar::new(arena_len as u64).with_style(
-                    ProgressStyle::with_template("Children: ({pos}/{len}) {per_sec}").unwrap(),
-                ))
                 .collect();
             next_color = !next_color;
         }
@@ -122,7 +127,7 @@ impl FutureMoves {
         color: Piece,
     ) -> impl Iterator<Item = usize> {
         let start_idx = self.arena.len();
-        self.arena.extend(
+        let mut new: Vec<Move> =
             // use [`Board::all_positions`] here instead of [`Board::possible_moves`]
             // because we use [`Board::what_if`] later and we want to reduce calls to [`Board::propegate_from_dry`]
             Board::all_positions()
@@ -134,9 +139,18 @@ impl FutureMoves {
                     winner: new_board.game_winner(color),
                     parent,
                     children: Vec::new(),
-                    value: 0,
-                }),
-        );
+                    value: new_board.count(self.agent_color) as i64 - new_board.count(!self.agent_color) as i64,
+                }).collect();
+
+        // we want to keep only the best move of the agent
+        if color == self.agent_color {
+            if new.len() > 1 {
+                new.sort_by_key(|x| x.compute_self_value(self.agent_color, 1));
+                new.drain(1..);
+            }
+        }
+
+        self.arena.extend(new);
 
         let new_indices = start_idx..self.arena.len();
 
@@ -277,7 +291,7 @@ pub struct ComplexAgent {
 
 impl ComplexAgent {
     pub const fn new(color: Piece) -> Self {
-        const MAX_DEPTH: usize = 8;
+        const MAX_DEPTH: usize = 17;
         const MAX_ARENA: usize = 100_000_000;
         Self {
             color,