From c2903f1712c40fc867cc0e80f8df132be4085880 Mon Sep 17 00:00:00 2001
From: YujieAki <124937574+YujieAki@users.noreply.github.com>
Date: Fri, 17 Feb 2023 18:47:09 -0800
Subject: [PATCH] Add files via upload

---
 Yujie AI/Yujie AI.iml     | 11 +++++++
 Yujie AI/src/Board.java   | 18 +++++++++++
 Yujie AI/src/ChessAI.java | 67 +++++++++++++++++++++++++++++++++++++++
 Yujie AI/src/Color.java   |  2 ++
 Yujie AI/src/Move.java    |  2 ++
 Yujie AI/src/Piece.java   |  2 ++
 6 files changed, 102 insertions(+)
 create mode 100644 Yujie AI/Yujie AI.iml
 create mode 100644 Yujie AI/src/Board.java
 create mode 100644 Yujie AI/src/ChessAI.java
 create mode 100644 Yujie AI/src/Color.java
 create mode 100644 Yujie AI/src/Move.java
 create mode 100644 Yujie AI/src/Piece.java

diff --git a/Yujie AI/Yujie AI.iml b/Yujie AI/Yujie AI.iml
new file mode 100644
index 0000000..c90834f
--- /dev/null
+++ b/Yujie AI/Yujie AI.iml	
@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<module type="JAVA_MODULE" version="4">
+  <component name="NewModuleRootManager" inherit-compiler-output="true">
+    <exclude-output />
+    <content url="file://$MODULE_DIR$">
+      <sourceFolder url="file://$MODULE_DIR$/src" isTestSource="false" />
+    </content>
+    <orderEntry type="inheritedJdk" />
+    <orderEntry type="sourceFolder" forTests="false" />
+  </component>
+</module>
\ No newline at end of file
diff --git a/Yujie AI/src/Board.java b/Yujie AI/src/Board.java
new file mode 100644
index 0000000..63afacf
--- /dev/null
+++ b/Yujie AI/src/Board.java	
@@ -0,0 +1,18 @@
+public class Board {
+    public getAllLegalMoves(){
+
+    }
+    public makeMove(){
+
+    }
+
+    public undoMove(){
+
+    }
+
+    public isGameover(){
+
+    }
+
+    public
+}
diff --git a/Yujie AI/src/ChessAI.java b/Yujie AI/src/ChessAI.java
new file mode 100644
index 0000000..7000e97
--- /dev/null
+++ b/Yujie AI/src/ChessAI.java	
@@ -0,0 +1,67 @@
+public class ChessAI {
+    private final int MAX_DEPTH = 4;
+
+    public Move findBestMove(Board board) {
+        int bestScore = Integer.MIN_VALUE;
+        Move bestMove = null;
+
+        for (Move move : board.getAllLegalMoves()) {
+            board.makeMove(move);
+            int score = minimax(board, MAX_DEPTH, Integer.MIN_VALUE, Integer.MAX_VALUE, false);
+            board.undoMove();
+
+            if (score > bestScore) {
+                bestScore = score;
+                bestMove = move;
+            }
+        }
+
+        return bestMove;
+    }
+
+    private int minimax(Board board, int depth, int alpha, int beta, boolean maximizingPlayer) {
+        if (depth == 0 || board.isGameOver()) {
+            return evaluateBoard(board);
+        }
+
+        int score;
+        if (maximizingPlayer) {
+            score = Integer.MIN_VALUE;
+            for (Move move : board.getAllLegalMoves()) {
+                board.makeMove(move);
+                score = Math.max(score, minimax(board, depth - 1, alpha, beta, false));
+                board.undoMove();
+                alpha = Math.max(alpha, score);
+                if (beta <= alpha) {
+                    break;
+                }
+            }
+        } else {
+            score = Integer.MAX_VALUE;
+            for (Move move : board.getAllLegalMoves()) {
+                board.makeMove(move);
+                score = Math.min(score, minimax(board, depth - 1, alpha, beta, true));
+                board.undoMove();
+                beta = Math.min(beta, score);
+                if (beta <= alpha) {
+                    break;
+                }
+            }
+        }
+
+        return score;
+    }
+
+    private int evaluateBoard(Board board) {
+        int score = 0;
+        for (Piece piece : board.getPieces()) {
+            if (piece.getColor() == Color.WHITE) {
+                score += piece.getValue();
+            } else {
+                score -= piece.getValue();
+            }
+        }
+        return score;
+    }
+}
+
diff --git a/Yujie AI/src/Color.java b/Yujie AI/src/Color.java
new file mode 100644
index 0000000..43f7623
--- /dev/null
+++ b/Yujie AI/src/Color.java	
@@ -0,0 +1,2 @@
+public class Color {
+}
diff --git a/Yujie AI/src/Move.java b/Yujie AI/src/Move.java
new file mode 100644
index 0000000..1bc888e
--- /dev/null
+++ b/Yujie AI/src/Move.java	
@@ -0,0 +1,2 @@
+public class Move {
+}
diff --git a/Yujie AI/src/Piece.java b/Yujie AI/src/Piece.java
new file mode 100644
index 0000000..91ec34b
--- /dev/null
+++ b/Yujie AI/src/Piece.java	
@@ -0,0 +1,2 @@
+public class Piece {
+}