proper minimax

wasm/o-x-rust/Cargo.lock

@@ -25,7 +25,7 @@ dependencies = [
 
 [[package]]
 name = "o-x-rust"
-version = "0.0.8"
+version = "0.0.9"
 dependencies = [
  "wasm-bindgen",
 ]

wasm/o-x-rust/Cargo.toml

@@ -4,7 +4,7 @@ description = "Noughts and crosses WASM algorithms"
 repository = "https://git.koval.net/cyclane/game-algorithms/src/branch/main/wasm/o-x-rust"
 license = "GNU GPLv3"
 readme = "README.md"
-version = "0.0.8"
+version = "0.0.9"
 edition = "2021"
 
 [lib]

wasm/o-x-rust/src/lib.rs

@@ -35,7 +35,7 @@ pub fn get_turn(me: u8, other: u8, first: bool, empty: usize) -> u8 {
 }
 
 #[wasm_bindgen]
-pub fn o0_get_score(me: u8, other: u8, first: bool, board: &[u8]) -> f64 {
+pub fn sa_get_score(me: u8, other: u8, first: bool, board: &[u8]) -> f64 {
 	let winner = find_winner(board);
 	if winner != 0 {
 		return if winner == me { 1.0 } else { -1.0 };
@@ -52,20 +52,20 @@ pub fn o0_get_score(me: u8, other: u8, first: bool, board: &[u8]) -> f64 {
 		let copy = &mut [0u8; 9];
 		copy.copy_from_slice(board);
 		copy[i] = get_turn(me, other, first, empty);
-		score += o0_get_score(me, other, first, copy);
+		score += sa_get_score(me, other, first, copy);
 	}
 	score
 }
 
 #[wasm_bindgen]
-pub fn o1d_get_score(me: u8, other: u8, first: bool, board: &[u8]) -> f64 {
-	let (outcomes, score) = o1_sub_get_score(me, other, first, board, 2, 2, 1);
+pub fn sa_rd_get_score(me: u8, other: u8, first: bool, board: &[u8]) -> f64 {
+	let (outcomes, score) = sa_r_sub_get_score(me, other, first, board, 2, 2, 1);
 	score as f64 / outcomes as f64
 }
 
 #[wasm_bindgen]
-pub fn o1nd_get_score(me: u8, other: u8, first: bool, board: &[u8]) -> f64 {
-	let (outcomes, score) = o1_sub_get_score(me, other, first, board, 1, 1, 0);
+pub fn sa_r_d_get_score(me: u8, other: u8, first: bool, board: &[u8]) -> f64 {
+	let (outcomes, score) = sa_r_sub_get_score(me, other, first, board, 1, 1, 0);
 	score as f64 / outcomes as f64
 }
 
@@ -74,7 +74,7 @@ pub fn o1nd_get_score(me: u8, other: u8, first: bool, board: &[u8]) -> f64 {
 // w: Win winning outcome score
 // d: Draw winning outcome score
 // (loose = 0)
-pub fn o1_sub_get_score(me: u8, other: u8, first: bool, board: &[u8], m: i32, w: i32, d: i32) -> (i32, i32) {
+pub fn sa_r_sub_get_score(me: u8, other: u8, first: bool, board: &[u8], m: i32, w: i32, d: i32) -> (i32, i32) {
 	let winner = find_winner(board);
 	if winner != 0 {
 		return if winner == me { (m, w) } else { (m, 0) };
@@ -92,33 +92,75 @@ pub fn o1_sub_get_score(me: u8, other: u8, first: bool, board: &[u8], m: i32, w:
 		let copy = &mut [0u8; 9];
 		copy.copy_from_slice(board);
 		copy[i] = get_turn(me, other, first, empty);
-		let (sub_outcomes, sub_score) = o1_sub_get_score(me, other, first, copy, m, w, d);
+		let (sub_outcomes, sub_score) = sa_r_sub_get_score(me, other, first, copy, m, w, d);
 		outcomes += sub_outcomes;
 		score += sub_score;
 	}
 	(outcomes, score)
 }
 
-// Optimization levels: o0, o1d, o1nd, o2
-// o0: minmax without optimizations
-// o1d: minmax with ratio optimization including draws
-// o1nd: minmax with ratio optimization excluding draws (draw = loose)
 #[wasm_bindgen]
-pub fn get_score(me: u8, other: u8, first: bool, board: &[u8], optimization_level: &str) -> f64 {
-	match optimization_level {
-		"o0" => o0_get_score(me, other, first, board),
-		"o1d" => o1d_get_score(me, other, first, board),
-		"o1nd" => o1nd_get_score(me, other, first, board),
+pub fn mm_get_score(me: u8, other: u8, first: bool, board: &[u8]) -> f64 {
+	mm_sub_get_score(me, other, first, board, 10.0, 0.0, 0.0)
+}
+
+#[wasm_bindgen]
+pub fn mm_d_get_score(me: u8, other: u8, first: bool, board: &[u8]) -> f64 {
+	mm_sub_get_score(me, other, first, board, 10.0, 0.0, 1.0)
+}
+
+// m = score (without depth) multiplier
+// dm = depth multiplier
+pub fn mm_sub_get_score(me: u8, other: u8, first: bool, board: &[u8], m: f64, depth: f64, dm: f64) -> f64 {
+	let winner = find_winner(board);
+	if winner != 0 {
+		return if winner == me { m - depth*dm } else { -m + depth*dm };
+	}
+	let empty = count_empty(board);
+	if empty == 0 {
+		return 0.0;
+	}
+	let turn = get_turn(me, other, first, empty);
+	let mut best = if turn == me { f64::MIN } else { f64::MAX };
+	for i in 0..9 {
+		if board[i] != 0 {
+			continue;
+		}
+		let copy = &mut [0u8; 9];
+		copy.copy_from_slice(board);
+		copy[i] = get_turn(me, other, first, empty);
+		let value = mm_sub_get_score(me, other, first, copy, m, depth + 1.0, dm);
+		best = if turn == me { best.max(value) } else { best.min(value) };
+	}
+	best
+}
+
+// Algorithms:
+// sa: score adding without optimizations
+// sa+rd: score adding with ratio optimization including draws
+// sa+r-d: score adding with ratio optimization excluding draws (draw = loose)
+// mm: minimax algorithm
+// mm+d: minmax algorithm with depth
+#[wasm_bindgen]
+pub fn get_score(me: u8, other: u8, first: bool, board: &[u8], algorithm: &str) -> f64 {
+	match algorithm {
+		"sa" => sa_get_score(me, other, first, board),
+		"sa+rd" => sa_rd_get_score(me, other, first, board),
+		"sa+r-d" => sa_r_d_get_score(me, other, first, board),
+		"mm" => mm_get_score(me, other, first, board),
+		"mm+d" => mm_d_get_score(me, other, first, board),
 		_ => 0.0
 	}
 }
 
-// Optimization levels: o0, o1d, o1nd, o2
-// o0: minmax without optimizations
-// o1d: minmax with ratio optimization including draws
-// o1nd: minmax with ratio optimization excluding draws (draw = loose)
+// Algorithms:
+// sa: score adding without optimizations
+// sa+rd: score adding with ratio optimization including draws
+// sa+r-d: score adding with ratio optimization excluding draws (draw = loose)
+// mm: minimax algorithm
+// mm+d: minmax algorithm with depth
 #[wasm_bindgen]
-pub fn predict(me: u8, other: u8, first: bool, board: &[u8], optimization_level: &str) -> usize {
+pub fn predict(me: u8, other: u8, first: bool, board: &[u8], algorithm: &str) -> usize {
 	let (mut max_p, mut max_s) = (0, f64::MIN);
 	let empty = count_empty(board);
 	if empty == 0 {
@@ -131,7 +173,7 @@ pub fn predict(me: u8, other: u8, first: bool, board: &[u8], optimization_level:
 		let copy = &mut [0u8; 9];
 		copy.copy_from_slice(board);
 		copy[i] = get_turn(me, other, first, empty);
-		let score = get_score(me, other, first, copy, optimization_level);
+		let score = get_score(me, other, first, copy, algorithm);
 		if score > max_s {
 			(max_p, max_s) = (i, score);
 		}