极小值极大值算法-井字棋

用极小值极大值算法写的井字棋：

#include 
#include 
#define COM -1 
#define MAN 1
#define STEP 9 
#define DRAW 0 
#define ROW 3 
#define COL 3
#define MAX_NUM 1000;


struct Move
{
	int x;
	int y;

};

//棋盘
int board[3][3] = { { 0,0,0 },
					{ 0,0,0 },
					{ 0,0,0 }
};
int tempBoard[3][3] = { { 0,0,0 },
						{ 0,0,0 },
						{ 0,0,0 }
};
//玩家
int player = MAN;
//最好的一步
Move bestMove;
//当前深度
int currentDepth;
//谁先走
bool MAN_first = true;


//判断输赢
int isWin() {
	int i, j;

	for (int i = 0; i < 3; i++)
	{
		if (board[i][0] + board[i][1] + board[i][2] == 3)
			return 1;
		else if (board[i][0] + board[i][1] + board[i][2] == -3)
			return -1;
	}
	for (int j = 0; j < 3; j++)
	{
		if (board[0][j] + board[1][j] + board[2][j] == 3)
			return 1;
		else if (board[0][j] + board[1][j] + board[2][j] == -3)
			return -1;
	}
	if (board[0][0] + board[1][1] + board[2][2] == 3 || board[0][2] + board[1][1] + board[2][0] == 3)
		return 1;
	else if (board[0][0] + board[1][1] + board[2][2] == -3 || board[0][2] + board[1][1] + board[2][0] == -3)
		return -1;
	else  return 0;

}

//评估函数
int evaluteMap() {

	bool flag = true;
	int i, j;

	if (isWin() == COM)
		return MAX_NUM;//如果计算机赢了，返回最大值 
	if (isWin() == MAN)
		return -MAX_NUM;//如果计算机输了，返回最小值 
	//for (i = 0; i < 3; i++)
	//	for (j = 0; j < 3; j++)
	//		if (board[i][j] == 0)
	//		{
	//			flag = false;
	//			break;
	//		}
	//if (flag)  //如果Flag为真  ， 棋盘都满了  就退出  
	//	return 0;


	int count = 0;//该变量用来表示评估函数的值
				  //将棋盘中的空格填满自己的棋子，既将棋盘数组中的0变为1
	for (i = 0; i < 3; i++)
		for (j = 0; j < 3; j++)
		{
			if (board[i][j] == 0)
				tempBoard[i][j] = COM;
			else
				tempBoard[i][j] = board[i][j];
		}
	//电脑一方
	//计算每一行中有多少行的棋子连成3个的
	for (i = 0; i < 3; i++)
		count += (tempBoard[i][0] + tempBoard[i][1] + tempBoard[i][2]) / 3;
	for (i = 0; i < 3; i++)
		count += (tempBoard[0][i] + tempBoard[1][i] + tempBoard[2][i]) / 3;
	count += (tempBoard[0][0] + tempBoard[1][1] + tempBoard[2][2]) / 3;
	count += (tempBoard[2][0] + tempBoard[1][1] + tempBoard[0][2]) / 3;



	//将棋盘中的空格填满对方的棋子，既将棋盘数组中的0变为-1
	for (i = 0; i < 3; i++)
		for (j = 0; j < 3; j++)
		{
			if (board[i][j] == 0)
				tempBoard[i][j] = MAN;
			else tempBoard[i][j] = board[i][j];
		}
	//对方
	//计算每一行中有多少行的棋子连成3个的
	for (i = 0; i < 3; i++)
		count += (tempBoard[i][0] + tempBoard[i][1] + tempBoard[i][2]) / 3;
	for (i = 0; i < 3; i++)
		count += (tempBoard[0][i] + tempBoard[1][i] + tempBoard[2][i]) / 3;
	count += (tempBoard[0][0] + tempBoard[1][1] + tempBoard[2][2]) / 3;
	count += (tempBoard[2][0] + tempBoard[1][1] + tempBoard[0][2]) / 3;




	return count;
}


void makeMove(Move curMove)
{
	board[curMove.x][curMove.y] = player;
	player = (player == COM) ? MAN : COM;
}

void unMakeMove(Move curMove) {
	board[curMove.x][curMove.y] = 0;
	player = (player == COM) ? MAN : COM;
}

//得到有空位的集合
int getMoveList(Move moveList[]) {
	int moveCount = 0;
	int i, j;
	for (i = 0; i < COL; i++)
	{
		for (j = 0; j < ROW; j++)
		{
			if (board[i][j] == 0)
			{
				moveList[moveCount].x = i;
				moveList[moveCount].y = j;
				moveCount++;
			}

		}
	}
	return moveCount; //返回一共多少个空的位置 
}


int miniMaxsearch(int depth)
{
	int value;  //估值 
	int bestValue = 0; //最好的估值
	int moveCount = 0;
	int i; int m, n;
	Move moveList[9];//保存可以下子的位置
	if (isWin() == COM || isWin() == MAN)
	{
		return evaluteMap();  //一般是返回极大极小值
	}
	//如果搜索深度耗尽 ， 返回估值 
	if (depth == 0)
	{
		return evaluteMap();
	}


	//根据不同的玩家 进行赋值 
	if (COM == player) {
		bestValue = -MAX_NUM;
	}
	else if (MAN == player)
	{
		bestValue = MAX_NUM;
	}

	//一共多少步
	moveCount = getMoveList(moveList);

	for (i = 0; i < moveCount; i++)
	{
		Move curMove = moveList[i];

		makeMove(curMove);
		value = miniMaxsearch(depth - 1);
		unMakeMove(curMove);

		if (player == COM)
		{
			if (value > bestValue)
			{
				bestValue = value;
				if (depth == currentDepth)
				{
					bestMove = curMove;
				}
			}
		}
		else if (player == MAN)
		{
			if (value < bestValue)
			{
				bestValue = value;
				if (depth == currentDepth)
				{
					bestMove = curMove;
				}
			}
		}

	}
	 
	return bestValue;
}


//打印棋盘 电脑X  ，玩家O 
void printBoard() {
	int i, j;
	for (i = 0; i < COL; i++)
	{
		printf("-------------\n");
		for (j = 0; j < ROW; j++)
		{
			if (board[i][j] == COM)
			{
				printf("| X ");
			}
			else if (board[i][j] == MAN)
			{
				printf("| O ");
			}
			else
			{
				printf("|   ");
			}

		}
		printf("|\n");
	}
	printf("-------------\n");

}



void com_play() {
	miniMaxsearch(currentDepth);
	board[bestMove.x][bestMove.y] = COM;

}

void man_play() {
	int x, y;
	printf("请输入位置坐标  e.g ：（0 0）为左上角 （2，2）为右下角 \n");
	scanf("%d", &x);
	scanf("%d", &y);

	while (x < 0 || x > 2 || y < 0 || y > 2)
	{
		printf("您输入的坐标错误，请重新输入:x:(0~2) , y:(0~2)\n");
		scanf("%d", &x);
		scanf("%d", &y);
	}
	while (board[x][y] != 0)
	{
		printf("该位置已有棋，请重新输入:\n");
		scanf("%d", &x);
		scanf("%d", &y);
	}

	board[x][y] = MAN;

}






void setFirst() {
	char c;
	printf("\nDo you want to play first? y -你先走  , n-电脑先走");
	for (c = getche(); c != 'Y'&&c != 'y'&&c != 'N'&&c != 'n'; c = getche());
	if (c == 'n' || c == 'N') {
		MAN_first = false;
	}
	printf("\n");
}


void main()
{
	currentDepth = 9;
	int step = 1;
	setFirst();
	printBoard();

	if (MAN_first) {
		player = MAN;
		for (step = 1; step <= STEP; )
		{
			man_play();
			printBoard();
			if (player == isWin()) {
				printf("您获胜了！！");
				break;
			}
			step++;
			currentDepth--;
			if (step == 10) {
				printf("平局 ~~~");
				break;
			}
			player = (player == COM) ? MAN : COM;
			com_play();
			printBoard();
			if (player == isWin()) {
				printf("很遗憾，电脑赢啦！！！");
				break;
			}
			step++;
			currentDepth--;
			player = (player == COM) ? MAN : COM;
		}
	}

	else
	{
		player = COM;
		for (step = 1; step <= STEP; )
		{
			com_play();

			printBoard();
			if (player == isWin()) {
				printf("很遗憾，电脑赢啦！！！");
				break;
			}
			step++;
			currentDepth--;
			if (step == 10) {
				printf("平局 ~~~");
				break;
			}
			player = (player == COM) ? MAN : COM;
			man_play();
			printBoard();
			if (player == isWin()) {
				printf("您获胜了！！");
				break;
			}
			step++;
			currentDepth--;
			player = (player == COM) ? MAN : COM;
		}
	}
	getch();
}