Tweaks to AI for correctness

front_end/src/ai.rs

@@ -216,7 +216,7 @@ fn get_block_amount(player: Turn, idx: usize, amount: usize, board: &BoardType)
     }
 
     // check right
-    count = 0;
+    // count = 0; // don't reset count, since horizontal may pass through idx
     temp_idx = idx;
     while temp_idx % (COLS as usize) < (COLS - 1) as usize {
         temp_idx += 1;
@@ -260,6 +260,21 @@ fn get_block_amount(player: Turn, idx: usize, amount: usize, board: &BoardType)
         }
     }
 
+    // check diagonal right up
+    // count = 0; // don't reset count as diagonal may pass through idx
+    temp_idx = idx;
+    while temp_idx % (COLS as usize) < (COLS - 1) as usize && temp_idx / (COLS as usize) > 0 {
+        temp_idx = temp_idx + 1 - COLS as usize;
+        if board[temp_idx].get() == opposite.into() {
+            count += 1;
+            if count >= amount {
+                return true;
+            }
+        } else {
+            break;
+        }
+    }
+
     // check diagonal right down
     count = 0;
     temp_idx = idx;
@@ -278,7 +293,7 @@ fn get_block_amount(player: Turn, idx: usize, amount: usize, board: &BoardType)
     }
 
     // check diagonal left up
-    count = 0;
+    // count = 0; // don't reset count as diagonal may pass through idx
     temp_idx = idx;
     while temp_idx % (COLS as usize) > 0 && temp_idx / (COLS as usize) > 0 {
         temp_idx = temp_idx - 1 - COLS as usize;
@@ -292,21 +307,6 @@ fn get_block_amount(player: Turn, idx: usize, amount: usize, board: &BoardType)
         }
     }
 
-    // check diagonal right up
-    count = 0;
-    temp_idx = idx;
-    while temp_idx % (COLS as usize) < (COLS - 1) as usize && temp_idx / (COLS as usize) > 0 {
-        temp_idx = temp_idx + 1 - COLS as usize;
-        if board[temp_idx].get() == opposite.into() {
-            count += 1;
-            if count >= amount {
-                return true;
-            }
-        } else {
-            break;
-        }
-    }
-
     // exhausted all possible potential wins, therefore does not block a win
     false
 }

front_end/src/state.rs

@@ -197,6 +197,15 @@ pub fn new_empty_board() -> BoardType {
     ]
 }
 
+pub fn board_deep_clone(board: &BoardType) -> BoardType {
+    let cloned_board = new_empty_board();
+    for i in 0..board.len() {
+        cloned_board[i].replace(board[i].get());
+    }
+
+    cloned_board
+}
+
 pub type PlacedType = [Rc<Cell<bool>>; 56];
 
 pub fn new_placed() -> PlacedType {