人工智能---alphabeta剪枝算法实现AI井子棋

AI的智能程度是跟你剪枝的层数相关的，越深越智能

#include <iostream>#include <cstring>#include <cmath>#include <cstdio>#include <cstdlib>#include <stack>#include <list>#include <iomanip>#include <algorithm> using namespace std;const int empty = 0;const int human = 1;const int comp = 2;int board[3][3];int counthad;int x, y;int pos;bool iswin(int value, int x, int y) //是否构成线取胜 {    if ((board[x][0] == value && board[x][1] == value && board[x][2] == value) || (board[0][y] == value && board[1][y] == value && board[2][y] == value        ) || (board[0][0] == value && board[1][1] == value && board[2][2] == value) ||        (board[0][2] == value && board[1][1] == value && board[2][0] == value))        return true;    else return false;}int aicaozuo(int value, int alpha, int beta, int &pos, int human_pos)  //扫描并决定下点 {    int win = 1, draw = 0, result, tmp;    int other = 3 - value;    if (human_pos != -1 && iswin(other, human_pos / 3, human_pos % 3))   //对手赢         return -win;    if (counthad == 9)     //9步走完平局开始         return draw;    for (int i = 0; i < 9; ++i) //开始向下寻找知道alpha>=beta，AI下的点    {        if (alpha >= beta)            break;        if (board[i / 3][i % 3])            continue;        board[i / 3][i % 3] = value;        counthad++;        result = -aicaozuo(other, -beta, -alpha, tmp, i);   //递归调用，向下一层搜索         if (result > alpha){            alpha = result;            pos = i;        }        board[i / 3][i % 3] = empty; //每次重新把找到的点置零         counthad--;    }    return alpha;}//显示棋盘 void display(){    for (int i = 0; i<3; i++){        for (int j = 0; j<3; j++){            if (board[i][j] == empty)                cout << "+";            else if (board[i][j] == human)                cout << "o";            else                cout << "x";        }        cout << endl;    }}void handhuman(){    //int x, y;    cin >> x >> y;    while (1)    {        if (!(x < 0 || x >= 3 || y <0 || y >= 3 || board[x][y]))            break;        cout << "该点无效，重新输入\n";        cin >> x >> y;    }    board[x][y] = 1;}void handcomp(){    //int pos;    aicaozuo(2, -1, 1, pos, -1);    //扫描并选择下子 pos     board[pos / 3][pos % 3] = 2;    counthad++;    display();}int main(){    while (1)    {        cout << "game start!\n";        cout << "please input:\n";        for (int i = 0; i < 3; ++i)//清空棋盘        for (int j = 0; j < 3; ++j)            board[i][j] = empty;        counthad = 0;        while (1)        {            handhuman();            if (iswin(1, x, y))  //返回真，则玩家赢             {                cout << "You win!\n";                break;            }            counthad++;            if (counthad == 9){                cout << "Draw!\n";//平局                 break;            }            handcomp();            if (iswin(2, pos / 3, pos % 3)){ //返回真，则电脑赢                 cout << "You lose!\n";                break;            }        }    }    return 0;}