From 83d4a9b50748df7fc12ee042c04e530885f0e746 Mon Sep 17 00:00:00 2001
From: Simon Gardling <titaniumtown@proton.me>
Date: Mon, 27 Jan 2025 14:40:36 -0500
Subject: [PATCH] improve prop range splitting: 2

---
 src/repr.rs | 47 ++++++++++++++++++-----------------------------
 1 file changed, 18 insertions(+), 29 deletions(-)

diff --git a/src/repr.rs b/src/repr.rs
index 326bd05..5325696 100644
--- a/src/repr.rs
+++ b/src/repr.rs
@@ -78,45 +78,34 @@ impl Board {
             return;
         };
 
-        for range in split(0, BOARD_SIZE - 1, i) {
+        let mut chains: Vec<Vec<(usize, usize)>> = split(0, BOARD_SIZE - 1, i)
+            .into_iter()
+            .map(|range| range.into_iter().map(|i| (i, j)).collect())
+            .collect();
+        chains.append(
+            &mut split(0, BOARD_SIZE - 1, j)
+                .into_iter()
+                .map(|range| range.into_iter().map(|j| (i, j)).collect())
+                .collect::<Vec<Vec<(usize, usize)>>>(),
+        );
+
+        for chain in chains {
             let mut chain_length: usize = 0;
-            for &new_i in &range {
-                let Some(piece) = self.get(new_i, j) else {
+
+            for &(new_i, new_j) in &chain {
+                let Some(piece) = self.get(new_i, new_j) else {
                     break;
                 };
                 if piece == &starting_color {
                     if chain_length > 0 {
                         // fill all opposite colors with this color
-                        let Some(i_o_s) = range.get(..chain_length) else {
+                        let Some(i_o_s) = chain.get(..chain_length) else {
                             break;
                         };
 
                         // fill all opposite colors with this color
-                        for i_o in i_o_s {
-                            self.place_and_prop_unchecked(*i_o, j, starting_color);
-                        }
-                    }
-                    break;
-                }
-                chain_length += 1;
-            }
-        }
-
-        for range in split(0, BOARD_SIZE - 1, j) {
-            let mut chain_length: usize = 0;
-            for &new_j in &range {
-                let Some(piece) = self.get(i, new_j) else {
-                    break;
-                };
-                if piece == &starting_color {
-                    if chain_length > 0 {
-                        let Some(j_o_s) = range.get(..chain_length) else {
-                            break;
-                        };
-
-                        // fill all opposite colors with this color
-                        for j_o in j_o_s {
-                            self.place_and_prop_unchecked(i, *j_o, starting_color);
+                        for &(i_o, j_o) in i_o_s {
+                            self.place_and_prop_unchecked(i_o, j_o, starting_color);
                         }
                     }
                     break;