hw(AI/4): Fix depth

1 files changed, 14 insertions, 10 deletions

diff --git a/Year 4/Artificial Intelligence/hw04/src/main.rs b/Year 4/Artificial Intelligence/hw04/src/main.rs
index 6bc55d0..933083b 100644
--- a/Year 4/Artificial Intelligence/hw04/src/main.rs
+++ b/Year 4/Artificial Intelligence/hw04/src/main.rs
@@ -57,8 +57,8 @@ fn game_over(board: &[[Tile; 3]; 3]) -> BoardResult {
 
 fn evaluate(board: &[[Tile; 3]; 3]) -> i32 {
     match game_over(board) {
-        BoardResult::WinO =>  10,
-        BoardResult::WinX => -10,
+        BoardResult::WinO =>  20,
+        BoardResult::WinX => -20,
         BoardResult::Continue => 0,
     }
 }
@@ -70,8 +70,12 @@ fn minimax(
     mut beta: i32,
     maximizer: bool,
 ) -> (i32, usize, usize) {
+    if depth == 0 {
+        return (0, 0, 0);
+    }
+
     let score = evaluate(board);
-    if score.abs() == 10 {
+    if score != 0 {
         return (score, 0, 0);
     }
 
@@ -82,11 +86,11 @@ fn minimax(
                 if board[row][col] != Tile::Empty { continue; }
 
                 board[row][col] = Tile::O;
-                let eval = minimax(board, depth + 1, alpha, beta, false);
+                let eval = minimax(board, depth - 1, alpha, beta, false);
                 board[row][col] = Tile::Empty;
 
                 if eval.0 > max_eval.0 {
-                    max_eval = (eval.0 - depth, row, col);
+                    max_eval = (eval.0, row, col);
                 }
 
                 alpha = max(alpha, eval.0);
@@ -104,11 +108,11 @@ fn minimax(
                 if board[row][col] != Tile::Empty { continue; }
 
                 board[row][col] = Tile::X;
-                let eval = minimax(board, depth + 1, alpha, beta, true);
+                let eval = minimax(board, depth - 1, alpha, beta, true);
                 board[row][col] = Tile::Empty;
 
                 if eval.0 < min_eval.0 {
-                    min_eval = (eval.0 + depth, row, col);
+                    min_eval = (eval.0, row, col);
                 }
 
                 beta = min(beta, eval.0);
@@ -135,8 +139,8 @@ fn player_move(board: &mut [[Tile; 3]; 3]) {
     board[x][y] = Tile::X;
 }
 
-fn computer_move(board: &mut [[Tile; 3]; 3]) {
-    let (_, x, y) = minimax(board, 0, i32::MIN, i32::MAX, false);
+fn computer_move(board: &mut [[Tile; 3]; 3], turn: i32) {
+    let (_, x, y) = minimax(board, 9 - turn, i32::MIN, i32::MAX, true);
     println!("Computer move: {x} {y}");
     board[x][y] = Tile::O;
 }
@@ -162,7 +166,7 @@ fn main() {
             break;
         }
 
-        computer_move(&mut board);
+        computer_move(&mut board, turn);
         print_board(board);
         if game_over(&board) != BoardResult::Continue {
             println!("Computer won!");