实现Tick Tac Toe小游戏。

#include <algorithm>
#include <iostream>
#include <string>
using namespace std;
class QP
{
public:
    void init() {
        for (int i = 0; i < 9; i++) {
            data[i] = EMPTY;
        }
        end = false;
        rs = "";
        count = 0;
        turn = PLAYER;
    }
    void show() {
        cout << endl;
        for (int i = 0; i < 9; i++) {
            cout << (data[i] == EMPTY ? '+' : (data[i] == PLAYER ? 'O' : 'X'))
                << ((i + 1) % 3 ? '\0' : '\n');
        }
        cout << endl;
    }
    pair<int, int> get() {
        if (turn == COMPUTER) {
            auto t = next();
            cout << "computer put in: " << t.first << " " << t.second << endl;
            return t;
        }
        int x, y;
        cout << "input x and y: ";
        cin >> x >> y;
        return make_pair(x, y);
    }
    pair<int, int> next() {
        int *clone_data = new int[9];
        for (int i = 0; i < 9; i++) {
            clone_data[i] = data[i];
        }
        int index = -1;
        cout << search(clone_data, COMPUTER, -99999, 99999, index) << endl;
        delete clone_data;
        return make_pair(index / 3, index % 3);
    }
    bool set(pair<int, int> &put) {
        int index = put.first * 3 + put.second;
        if (data[index] != EMPTY) {
            return false;
        }
        count++;
        data[index] = turn;
        return true;
    }
    bool hasLine(int *t) {;
        return (t[0] != EMPTY && t[0] == t[1] && t[1] == t[2])
            || (t[3] != EMPTY && t[3] == t[4] && t[4] == t[5])
            || (t[6] != EMPTY && t[6] == t[7] && t[7] == t[8])
            || (t[0] != EMPTY && t[0] == t[3] && t[3] == t[6])
            || (t[1] != EMPTY && t[1] == t[4] && t[4] == t[7])
            || (t[2] != EMPTY && t[2] == t[5] && t[5] == t[8])
            || (t[0] != EMPTY && t[0] == t[4] && t[4] == t[8])
            || (t[2] != EMPTY && t[2] == t[4] && t[4] == t[6]);
    }
    void freshStateAfter(pair<int, int> &put) {
        bool line = hasLine(data);
        if (!line) {
            if (count == 9) {
                rs = "draw...";
                end = true;
            }
            return;
        }
        if (turn == PLAYER) {
            rs = "you win!";
        }
        else if (turn == COMPUTER) {
            rs = "you lose";
        }
        end = true;
    }
    void toggleTurn() {
        if (turn == PLAYER) {
            turn = COMPUTER;
        }
        else {
            turn = PLAYER;
        }
    }
    void start() {
        init();
        cout << "game start" << endl;
        while (!end) {
            show();
            auto put = get();
            if (set(put)) {
                freshStateAfter(put);
                toggleTurn();
            }
        }
        show();
        cout << rs << endl << endl;
    }
private:
    int search(int *node, int whoseTurn, int alpha, int beta, int &pos) {    
        if (hasLine(node)) {
            return whoseTurn == COMPUTER ? -1 : 1;
        }
        else {
            bool isDraw = true;
            for (int i = 0; i < 9; i++) {
                if (node[i] == EMPTY) {
                    isDraw = false;
                    break;
                }
            }
            if (isDraw) {
                return 0;
            }
        }
        int t, tpos;
        for (int i = 0; i < 9; i++) {
            if (node[i] == EMPTY) {
                if (whoseTurn == COMPUTER) {
                    node[i] = COMPUTER;
                    t = search(node, PLAYER, alpha, beta, tpos);
                    node[i] = EMPTY;
                    if (t > alpha) {
                        alpha = t;
                        pos = i;
                    }
                    if (beta <= alpha) {
                        return alpha;
                    }    
                }
                else if (whoseTurn == PLAYER) {
                    node[i] = PLAYER;
                    t = search(node, COMPUTER, alpha, beta, tpos);
                    node[i] = EMPTY;
                    if (t < beta) {
                        beta = t;
                    }
                    if (beta <= alpha) {
                        return beta;
                    }
                }
            }
        }
        return whoseTurn == COMPUTER ? alpha : beta;
    }
    string rs;
    int turn, count;
    bool end;
    int data[9];
    static int EMPTY, PLAYER, COMPUTER;
};
int QP::EMPTY = 0;
int QP::PLAYER = 1;
int QP::COMPUTER = -1;
int main() {
    while (true) {
        QP q;
        q.start();
    }
}