我已经用MiniMax实现了一个TicTacToe algorythm,但问题是计算机总是在下一个可能的位置放置一个'x'而不是评估游戏。有人知道为什么吗? (问题只能出现在MiniMax函数或nextMove函数中。) 非常感谢提前!! 这是代码:
int MiniMax(struct Game g, enum Symbol pl){
int score;
if (pl==CROSS)
{
score = -98765;
}
else score = 98765;
int temp_cross =0;
int temp_circle =0;
//base case
if (game_over(g) == CROSS)
return 10;
else if (game_over(g) == CIRCLE)
return -10;
else if (game_over(g) == FULL)
return 0;
int x,y;
for (y=0; y<SIZE_Y_AXIS; y++)
{
for (x=0; x<SIZE_X_AXIS; x++)
{
if (g.board.fields[x][y] == NONE)
{
if (pl == CROSS)
g.board.fields[x][y] = CROSS;
else g.board.fields[x][y] = CIRCLE;
if (pl == CROSS)
temp_cross= MiniMax(g, CIRCLE);
else temp_circle = MiniMax(g, CROSS);
g.board.fields[x][y] = NONE;
if ((pl == CROSS) && (temp_cross > score))
score = temp_cross;
else if ((pl == CIRCLE) && (temp_circle < score))
score = temp_circle;
}
}
}
return score;
};
int nextMove(struct Game g, enum Symbol player){
int score_cross = -865435;
int score_cross_temp = 0;
int cross_position = 1;
int score_circle = 876545;
int score_circle_temp = 0;
int circle_position = 1;
int x,y;
for (y=0; y<SIZE_Y_AXIS; y++)
{
for (x=0; x<SIZE_X_AXIS; x++)
{
if (g.board.fields[x][y] == NONE)
{
if (player == CROSS)
{
score_cross_temp = MiniMax(g, CROSS);
printf("%d ",MiniMax(g, CROSS));
if (score_cross_temp > score_cross)
{
score_cross = score_cross_temp;
cross_position = (y)*3 + x+1;
}
}
else if (player == CIRCLE)
{
score_circle_temp = MiniMax(g, CIRCLE);
if (score_cross_temp < score_circle)
{
score_circle = score_circle_temp;
circle_position = (y)*3 + x+1;
}
}
}
}
}
if (player == CROSS)
{
//printf("%d",cross_position);
return cross_position;
}
else
{
//printf("%d",circle_position);
return circle_position;
}
};
答案 0 :(得分:0)
我相信您的代码中存在错误。您将得分初始化为10,将临时变量初始化为任意高和低数字。这是倒退。无论如何,TempCircle和TempCross都被覆盖了我对minimax的调用。必须像这样设置得分变量。取代
int score = 10;
int temp_cross = -9876543;
int temp_circle = 9876543;
与
int score;
if(pl==cross){
score = 9876543
}
else{
score = -9876543
}
int temp_cross;
int temp_circle;
你的nextMove函数似乎还有另一个错误。我假设其目的是迭代所有可能的移动,找到具有最高极小极大值的那个,并返回该移动(如果我错了,请纠正我)。这不是功能的作用。它迭代所有的动作,但不会做出任何动作。除了更新移动之外,x和y从未被使用过。你本质上是多次调用相同的minimax。相反,我要么彻底摆脱这个功能,因为有一种方法可以在minimax函数中执行此操作,或者修复此函数。要修复该功能,我会将其更改为:
int nextMove(struct Game g, enum Symbol player){
int score_cross = -865435;
int score_cross_temp = 0;
int cross_position = 1;
int score_circle = 876545;
int score_circle_temp = 0;
int circle_position = 1;
int x,y;
for (y=0; y<SIZE_Y_AXIS; y++)
{
for (x=0; x<SIZE_X_AXIS; x++)
{
if (g.board.fields[x][y] == NONE)
{
if (player == CROSS)
{
g.board.fields[x][y] = CROSS;
score_cross_temp = MiniMax(g, CIRCLE);
printf("%d ",MiniMax(g, CROSS));
g.board.fields[x][y] = NONE;
if (score_cross_temp > score_cross)
{
score_cross = score_cross_temp;
cross_position = (y)*3 + x+1;
}
}
else if (player == CIRCLE)
{
g.board.fields[x][y] = CIRCLE;
score_circle_temp = MiniMax(g, CROSS);
g.board.fields[x][y] = NONE;
if (score_cross_temp < score_circle)
{
score_circle = score_circle_temp;
circle_position = (y)*3 + x+1;
}
}
}
}
}
if (player == CROSS)
{
//printf("%d",cross_position);
return cross_position;
}
else
{
//printf("%d",circle_position);
return circle_position;
}
};
或者您可以编辑minimax以跟踪对该功能的调用。如果它是第一个递归调用(根),则跟踪移动本身及其值。然后返回移动。