【发布时间】：2021-01-19 21:36:18
【问题描述】：
我已经调试了好几天了，但我不知道我在井字游戏和人工智能的这段代码中做错了什么（我知道它不是真正的人工智能，但是......）我选择了因为这是 Alpha-Beta 修剪。它的 7x7 板，因此对于纯 minimax 实现来说太重了。
我的问题是我无法弄清楚为什么 Alpha-Beta 没有阻止玩家停止游戏并等待玩家移动并使用对他有利的正确移动，或者只是简单地平局。
我已经决定棋盘中心的得分（最终得分）比棋盘边缘的得分多。我相信更多地移动到中心将比边缘的移动有更多的成功机会，这就是为什么我制作了评估该移动的 AddScoreToMove 函数。
为了确保 eval 函数将检查板上所有可能的移动，我没有使该函数作为查找第一个 xxx（例如在 row0 和 col0、col1、col2 处）并返回（因为可能有 4X 或 4O）。 4X 或 4O 的得分也比其他得分高得多，应该被视为胜利。
此刻我的PCplayer(O's)是这样玩的
谁能告诉我我做错了什么？这是我的第二个 AI 程序，第一个是在 3x3 板上使用 minimax 的程序，效果很好。
C#代码如下
VB.NET 代码：
Public Class Form1
Dim board As Char(,) = {
{" ", " ", " ", " ", " ", " ", " "},
{" ", " ", " ", " ", " ", " ", " "},
{" ", " ", " ", " ", " ", " ", " "},
{" ", " ", " ", " ", " ", " ", " "},
{" ", " ", " ", " ", " ", " ", " "},
{" ", " ", " ", " ", " ", " ", " "},
{" ", " ", " ", " ", " ", " ", " "}}
Class Move
Public row, col As Integer
End Class
Dim BestMoveRow As Integer = 0
Dim BestMoveCol As Integer = 0
Dim BestMoveScore As Integer = 0
Shared player As Char = "X", opponent As Char = "O"
Shared Function AddScoreToMove(thatMove As Move) As Integer
Dim row As Integer = thatMove.row
Dim col As Integer = thatMove.col
'0 score, move is at border
If ((row >= 1 And row <= 5) And col = 0) Then
Return 0
ElseIf ((row >= 1 And row <= 5) And col = 6) Then
Return 0
ElseIf (row = 0 And (col >= 0 And col <= 6)) Then
Return 0
ElseIf (row = 6 And (col >= 0 And col <= 6)) Then
Return 0
End If
'1 score, thatMove is at border +1
If ((row >= 2 And row <= 4) And col = 1) Then
Return 1
ElseIf ((row >= 2 And row <= 4) And col = 5) Then
Return 1
ElseIf (row = 1 And (col >= 1 And col <= 5)) Then
Return 1
ElseIf (row = 5 And (col >= 1 And col <= 5)) Then
Return 1
End If
'2 score, thatMove is at border +2
If (row = 2 And col = 2) Then
Return 2
ElseIf (row = 2 And col = 4) Then
Return 2
ElseIf (row = 2 And (col >= 2 And col <= 4)) Then
Return 2
ElseIf (row = 4 And (col >= 2 And col <= 4)) Then
Return 2
End If
'3 Center thatMove
If (row = 3 And col <= 3) Then
Return 3
End If
Return 0 'error not added lane
End Function
Private Shared Function eval(ByVal b As Char(,)) As Integer
Dim playerScorerow As Integer = 0
Dim playerScorecol As Integer = 0
Dim playerScorecross As Integer = 0
Dim pcScorerow As Integer = 0
Dim pcScorecol As Integer = 0
Dim pcScorecross As Integer = 0
''EVALUATE rows
For row As Integer = 0 To 3
For col As Integer = 0 To 6
'initialize moves to evaluate
Dim move3 As New Move With {
.row = row + 3,
.col = col
}
Dim move2 As New Move With {
.row = row + 2,
.col = col
}
Dim move1 As New Move With {
.row = row + 1,
.col = col
}
Dim move0 As New Move With {
.row = row,
.col = col
}
If Not b(row, col) = " " Then 'ITS NOT EMPTY - PLAYER OR PC MOVED HERE
Dim moveScore As Integer = AddScoreToMove(move0) 'EVALUATE THAT MOVE
If b(row, col) = b(row + 1, col) Then 'THERE IS 2 X or 2 O
Dim move1Score As Integer = AddScoreToMove(move1)
If b(row + 1, col) = b(row + 2, col) Then 'THERE IS 3x or 3O
Dim move2Score As Integer = AddScoreToMove(move2)
If b(row + 2, col) = b(row + 3, col) Then 'THERE IS 4X or 4O
Dim move3Score As Integer = AddScoreToMove(move3)
If b(row, col) = player Then 'PLAYER HAVE 4X HERE
playerScorerow = Math.Max(playerScorerow, 100 + move3Score + move2Score + move1Score + moveScore) 'GET HIGHEST OF ALL EVALUATIONS OF THAT FOR LOOPS
ElseIf b(row, col) = opponent Then 'PC HAVE 4O HERE
pcScorerow = Math.Min(pcScorerow, -100 - move3Score - move2Score - move1Score - moveScore)
End If
End If
If b(row, col) = player Then
playerScorerow = Math.Max(playerScorerow, 5 + move2Score + move1Score + moveScore)
ElseIf b(row, col) = opponent Then
pcScorerow = Math.Min(pcScorerow, -5 - move2Score - move1Score - moveScore)
End If
End If
If b(row, col) = player Then
playerScorerow = Math.Max(playerScorerow, 2 + move1Score + moveScore)
ElseIf b(row, col) = opponent Then
pcScorerow = Math.Min(pcScorerow, -2 - move1Score - moveScore)
End If
End If
If b(row, col) = player Then
playerScorerow = Math.Max(playerScorerow, moveScore)
ElseIf b(row, col) = opponent Then
pcScorerow = Math.Min(pcScorerow, -moveScore)
End If
End If
Next
Next
''col win
For row As Integer = 0 To 6
For col As Integer = 0 To 3
Dim move3 As New Move With {
.row = row + 3,
.col = col
}
Dim move2 As New Move With {
.row = row + 2,
.col = col
}
Dim move1 As New Move With {
.row = row + 1,
.col = col
}
Dim move0 As New Move With {
.row = row,
.col = col
}
If Not b(row, col) = " " Then
Dim moveScore As Integer = AddScoreToMove(move0)
If b(row, col) = b(row, col + 1) Then
Dim moveScore1 As Integer = AddScoreToMove(move1)
If b(row, col + 1) = b(row, col + 2) Then
Dim moveScore2 As Integer = AddScoreToMove(move2)
If b(row, col + 2) = b(row, col + 3) Then
Dim moveScore3 As Integer = AddScoreToMove(move3)
If b(row, col) = player Then
playerScorerow = Math.Max(playerScorerow, 100 + moveScore3 + moveScore2 + moveScore1 + moveScore)
ElseIf b(row, col) = opponent Then
pcScorerow = Math.Min(pcScorerow, -100 - moveScore3 - moveScore2 - moveScore1 - moveScore)
End If
End If
If b(row, col) = player Then
playerScorerow = Math.Max(playerScorerow, 5 + moveScore2 + moveScore1 + moveScore)
ElseIf b(row, col) = opponent Then
pcScorerow = Math.Min(pcScorerow, -5 - moveScore2 - moveScore1 - moveScore)
End If
End If
If b(row, col) = player Then
playerScorerow = Math.Max(playerScorerow, 2 + moveScore1 + moveScore)
ElseIf b(row, col) = opponent Then
pcScorerow = Math.Min(pcScorerow, -2 - moveScore1 - moveScore)
End If
End If
If b(row, col) = player Then
playerScorerow = Math.Max(playerScorerow, moveScore)
ElseIf b(row, col) = opponent Then
pcScorerow = Math.Min(pcScorerow, -moveScore)
End If
End If
Next
Next
'NOT FULLY IMPLEMENTED
'cross win
For row As Integer = 0 To 3
For col As Integer = 0 To 3
If Not b(row, col) = " " Then
If (b(row, col) = b(row + 1, col + 1) AndAlso b(row + 1, col + 1) = b(row + 2, col + 2) AndAlso b(row + 2, col + 2) = b(row + 3, col + 3)) Then
If b(row, col) = player Then
Return +10
ElseIf b(row, col) = opponent Then
Return -10
End If
End If
End If
Next
Next
'NOT FULLY IMPLEMENTED
'cross win
For row As Integer = 0 To 3
For col As Integer = 3 To 6
If Not b(row, col) = " " Then
If (b(row, col) = b(row + 1, col - 1) AndAlso b(row + 1, col - 1) = b(row + 2, col - 2) AndAlso b(row + 2, col - 2) = b(row + 3, col - 3)) Then
If b(row, col) = player Then
Return +10
ElseIf b(row, col) = opponent Then
Return -10
End If
End If
End If
Next
Next
Dim scoreValues() As Integer = {playerScorerow, playerScorecol, playerScorecross, pcScorerow, pcScorecol, pcScorecross}
Dim max = scoreValues.OrderByDescending(Function(z) Math.Abs(z)).FirstOrDefault()
Return max
End Function
Private Shared Function MiniMax(ByVal board As Char(,), ByVal machineMove As Boolean, ByVal depth As Integer) As Integer
Const alpha As Integer = -10_000
Const beta As Integer = 10_000
Return AlphaBetaPruning(board, machineMove, depth, beta, alpha)
End Function
Private Shared Function AlphaBetaPruning(ByVal board As Char(,), ByVal machineMove As Boolean, ByVal depth As Integer, ByVal beta As Integer, ByVal alpha As Integer) As Integer
If depth = 0 Then Return eval(board)
If machineMove Then 'min PC MOVE
For i As Integer = 0 To 6
For j As Integer = 0 To 6
If board(i, j) = " " Then
board(i, j) = opponent
Dim score As Integer = Math.Min(AlphaBetaPruning(board, Not machineMove, depth - 1, beta, alpha), eval(board))
board(i, j) = " "
If score < beta Then
Form1.BestMoveRow = i
Form1.BestMoveCol = j
Form1.BestMoveScore = score
beta = score
End If
If alpha >= beta Then Exit For 'cutoff
End If
Next
Next
Return beta
Else 'max PLAYER MOVE
For i As Integer = 0 To 6
For j As Integer = 0 To 6
If board(i, j) = " " Then
board(i, j) = player
Dim score As Integer = Math.Max(AlphaBetaPruning(board, Not machineMove, depth - 1, beta, alpha), eval(board))
board(i, j) = " "
If score > alpha Then
alpha = score
End If
If alpha >= beta Then Exit For
End If
Next
Next
Return alpha
End If
End Function
End Class
C#代码
public class Form1
{
private char[,] board = new[] { { " ", " ", " ", " ", " ", " ", " " }, { " ", " ", " ", " ", " ", " ", " " }, { " ", " ", " ", " ", " ", " ", " " }, { " ", " ", " ", " ", " ", " ", " " }, { " ", " ", " ", " ", " ", " ", " " }, { " ", " ", " ", " ", " ", " ", " " }, { " ", " ", " ", " ", " ", " ", " " } };
class Move
{
public int row, col;
}
private int BestMoveRow = 0;
private int BestMoveCol = 0;
private int BestMoveScore = 0;
private static char player = "X";
private static char opponent = "O";
public static int AddScoreToMove(Move thatMove)
{
int row = thatMove.row;
int col = thatMove.col;
// 0 score, move is at border
if (((row >= 1 & row <= 5) & col == 0))
return 0;
else if (((row >= 1 & row <= 5) & col == 6))
return 0;
else if ((row == 0 & (col >= 0 & col <= 6)))
return 0;
else if ((row == 6 & (col >= 0 & col <= 6)))
return 0;
// 1 score, thatMove is at border +1
if (((row >= 2 & row <= 4) & col == 1))
return 1;
else if (((row >= 2 & row <= 4) & col == 5))
return 1;
else if ((row == 1 & (col >= 1 & col <= 5)))
return 1;
else if ((row == 5 & (col >= 1 & col <= 5)))
return 1;
// 2 score, thatMove is at border +2
if ((row == 2 & col == 2))
return 2;
else if ((row == 2 & col == 4))
return 2;
else if ((row == 2 & (col >= 2 & col <= 4)))
return 2;
else if ((row == 4 & (col >= 2 & col <= 4)))
return 2;
// 3 Center thatMove
if ((row == 3 & col <= 3))
return 3;
return 0; // error not added lane
}
private static int eval(char[,] b)
{
int playerScorerow = 0;
int playerScorecol = 0;
int playerScorecross = 0;
int pcScorerow = 0;
int pcScorecol = 0;
int pcScorecross = 0;
// 'EVALUATE rows
for (int row = 0; row <= 3; row++)
{
for (int col = 0; col <= 6; col++)
{
// initialize moves to evaluate
Move move3 = new Move()
{
row = row + 3,
col = col
};
Move move2 = new Move()
{
row = row + 2,
col = col
};
Move move1 = new Move()
{
row = row + 1,
col = col
};
Move move0 = new Move()
{
row = row,
col = col
};
if (!b[row, col] == " ")
{
int moveScore = AddScoreToMove(move0); // EVALUATE THAT MOVE
if (b[row, col] == b[row + 1, col])
{
int move1Score = AddScoreToMove(move1);
if (b[row + 1, col] == b[row + 2, col])
{
int move2Score = AddScoreToMove(move2);
if (b[row + 2, col] == b[row + 3, col])
{
int move3Score = AddScoreToMove(move3);
if (b[row, col] == player)
playerScorerow = Math.Max(playerScorerow, 100 + move3Score + move2Score + move1Score + moveScore); // GET HIGHEST OF ALL EVALUATIONS OF THAT FOR LOOPS
else if (b[row, col] == opponent)
pcScorerow = Math.Min(pcScorerow, -100 - move3Score - move2Score - move1Score - moveScore);
}
if (b[row, col] == player)
playerScorerow = Math.Max(playerScorerow, 5 + move2Score + move1Score + moveScore);
else if (b[row, col] == opponent)
pcScorerow = Math.Min(pcScorerow, -5 - move2Score - move1Score - moveScore);
}
if (b[row, col] == player)
playerScorerow = Math.Max(playerScorerow, 2 + move1Score + moveScore);
else if (b[row, col] == opponent)
pcScorerow = Math.Min(pcScorerow, -2 - move1Score - moveScore);
}
if (b[row, col] == player)
playerScorerow = Math.Max(playerScorerow, moveScore);
else if (b[row, col] == opponent)
pcScorerow = Math.Min(pcScorerow, -moveScore);
}
}
}
// 'col win
for (int row = 0; row <= 6; row++)
{
for (int col = 0; col <= 3; col++)
{
Move move3 = new Move()
{
row = row + 3,
col = col
};
Move move2 = new Move()
{
row = row + 2,
col = col
};
Move move1 = new Move()
{
row = row + 1,
col = col
};
Move move0 = new Move()
{
row = row,
col = col
};
if (!b[row, col] == " ")
{
int moveScore = AddScoreToMove(move0);
if (b[row, col] == b[row, col + 1])
{
int moveScore1 = AddScoreToMove(move1);
if (b[row, col + 1] == b[row, col + 2])
{
int moveScore2 = AddScoreToMove(move2);
if (b[row, col + 2] == b[row, col + 3])
{
int moveScore3 = AddScoreToMove(move3);
if (b[row, col] == player)
playerScorerow = Math.Max(playerScorerow, 100 + moveScore3 + moveScore2 + moveScore1 + moveScore);
else if (b[row, col] == opponent)
pcScorerow = Math.Min(pcScorerow, -100 - moveScore3 - moveScore2 - moveScore1 - moveScore);
}
if (b[row, col] == player)
playerScorerow = Math.Max(playerScorerow, 5 + moveScore2 + moveScore1 + moveScore);
else if (b[row, col] == opponent)
pcScorerow = Math.Min(pcScorerow, -5 - moveScore2 - moveScore1 - moveScore);
}
if (b[row, col] == player)
playerScorerow = Math.Max(playerScorerow, 2 + moveScore1 + moveScore);
else if (b[row, col] == opponent)
pcScorerow = Math.Min(pcScorerow, -2 - moveScore1 - moveScore);
}
if (b[row, col] == player)
playerScorerow = Math.Max(playerScorerow, moveScore);
else if (b[row, col] == opponent)
pcScorerow = Math.Min(pcScorerow, -moveScore);
}
}
}
// NOT FULLY IMPLEMENTED
// cross win
for (int row = 0; row <= 3; row++)
{
for (int col = 0; col <= 3; col++)
{
if (!b[row, col] == " ")
{
if ((b[row, col] == b[row + 1, col + 1] && b[row + 1, col + 1] == b[row + 2, col + 2] && b[row + 2, col + 2] == b[row + 3, col + 3]))
{
if (b[row, col] == player)
return +10;
else if (b[row, col] == opponent)
return -10;
}
}
}
}
// NOT FULLY IMPLEMENTED
// cross win
for (int row = 0; row <= 3; row++)
{
for (int col = 3; col <= 6; col++)
{
if (!b[row, col] == " ")
{
if ((b[row, col] == b[row + 1, col - 1] && b[row + 1, col - 1] == b[row + 2, col - 2] && b[row + 2, col - 2] == b[row + 3, col - 3]))
{
if (b[row, col] == player)
return +10;
else if (b[row, col] == opponent)
return -10;
}
}
}
}
int[] scoreValues = new[] { playerScorerow, playerScorecol, playerScorecross, pcScorerow, pcScorecol, pcScorecross };
var max = scoreValues.OrderByDescending(z => Math.Abs(z)).FirstOrDefault();
return max;
}
private static int MiniMax(char[,] board, bool machineMove, int depth)
{
const int alpha = -10_000;
const int beta = 10_000;
return AlphaBetaPruning(board, machineMove, depth, beta, alpha);
}
private static int AlphaBetaPruning(char[,] board, bool machineMove, int depth, int beta, int alpha)
{
if (depth == 0)
return eval(board);
if (machineMove)
{
for (int i = 0; i <= 6; i++)
{
for (int j = 0; j <= 6; j++)
{
if (board[i, j] == " ")
{
board[i, j] = opponent;
int score = Math.Min(AlphaBetaPruning(board, !machineMove, depth - 1, beta, alpha), eval(board));
board[i, j] = " ";
if (score < beta)
{
Form1.BestMoveRow = i;
Form1.BestMoveCol = j;
Form1.BestMoveScore = score;
beta = score;
}
if (alpha >= beta)
break; // cutoff
}
}
}
return beta;
}
else
{
for (int i = 0; i <= 6; i++)
{
for (int j = 0; j <= 6; j++)
{
if (board[i, j] == " ")
{
board[i, j] = player;
int score = Math.Max(AlphaBetaPruning(board, !machineMove, depth - 1, beta, alpha), eval(board));
board[i, j] = " ";
if (score > alpha)
alpha = score;
if (alpha >= beta)
break;
}
}
}
return alpha;
}
}
}
【问题讨论】：
-
你应该调试，监控变量，看看哪里出错了。
-
7x7 棋盘的游戏规则是什么？
-
@user3386109 在大多数情况下，用 4O 或 4X 获胜是有规则的，但我看到了 5 的变化
-
当它是一个表单级别的变量时，你为什么要将 board 传递给
AlphaBetaPruning？ -
@Mary 这当然是错误的，但不能解决我问的问题；）
标签： c# vb.net algorithm artificial-intelligence minimax