写一个C++的五子棋程序

以下是一个简单的命令行五子棋程序，使用 C++ 编写：

#include <iostream>
#include <vector>
#include <utility>

using namespace std;

const int BOARD_SIZE = 15;
const char EMPTY = ' ';
const char BLACK = 'X';
const char WHITE = 'O';

class Board {
public:
    Board() {
        for (int i = 0; i < BOARD_SIZE; i++) {
            vector<char> row(BOARD_SIZE, EMPTY);
            board.push_back(row);
        }
    }

    void display() const {
        cout << "  ";
        for (int i = 0; i < BOARD_SIZE; i++) {
            cout << i << " ";
        }
        cout << endl;
        for (int i = 0; i < BOARD_SIZE; i++) {
            cout << i << " ";
            for (int j = 0; j < BOARD_SIZE; j++) {
                cout << board[i][j] << " ";
            }
            cout << endl;
        }
    }

    bool is_valid_move(int x, int y) const {
        return x >= 0 && x < BOARD_SIZE && y >= 0 && y < BOARD_SIZE && board[x][y] == EMPTY;
    }

    bool make_move(int x, int y, char player) {
        if (!is_valid_move(x, y)) {
            return false;
        }
        board[x][y] = player;
        return true;
    }

    bool has_five_in_a_row(int x, int y) const {
        char player = board[x][y];
        int count;

        // check horizontal
        count = 1;
        for (int i = y - 1; i >= 0 && board[x][i] == player; i--) {
            count++;
        }
        for (int i = y + 1; i < BOARD_SIZE && board[x][i] == player; i++) {
            count++;
        }
        if (count >= 5) {
            return true;
        }

        // check vertical
        count = 1;
        for (int i = x - 1; i >= 0 && board[i][y] == player; i--) {
            count++;
        }
        for (int i = x + 1; i < BOARD_SIZE && board[i][y] == player; i++) {
            count++;
        }
        if (count >= 5) {
            return true;
        }

        // check diagonal
        count = 1;
        for (int i = x - 1, j = y - 1; i >= 0 && j >= 0 && board[i][j] == player; i--, j--) {
            count++;
        }
        for (int i = x + 1, j = y + 1; i < BOARD_SIZE && j < BOARD_SIZE && board[i][j] == player; i++, j++) {
            count++;
        }
        if (count >= 5) {
            return true;
        }

        // check anti-diagonal
        count = 1;
        for (int i = x - 1, j = y + 1; i >= 0 && j < BOARD_SIZE && board[i][j] == player; i--, j++) {
            count++;
        }
        for (int i = x + 1, j = y - 1; i < BOARD_SIZE && j >= 0 && board[i][j] == player; i++, j--) {
            count++;
        }
        if (count >= 5) {
            return true;
        }

        return false;
    }

private:
    vector<vector<char>> board;
};

int main() {
    Board board;

    char current_player = BLACK;
    while (true) {
        board.display();
        cout << "Current player: " << current_player << endl;

        int x, y;
        while (true) {
            cout << "Enter x and y coordinates (0-14): ";
            cin >> x >> y;
            if (board.is_valid_move(x, y)) {
                break;
            }
            cout << "Invalid move. Please try again." << endl;
        }

        if (!board.make_move(x, y, current_player)) {
            cout << "Invalid move. Please try again." << endl;
            continue;
        }

        if (board.has_five_in_a_row(x, y)) {
            cout << "Player " << current_player << " wins!" << endl;
            break;
        }

        current_player = (current_player == BLACK) ? WHITE : BLACK;
    }

    return 0;
}

该程序使用了一个 `Board` 类来表示五子棋棋盘，并实现了以下方法：

- `display()`：打印当前棋盘状态。
- `is_valid_move()`：判断一个坐标是否为有效的落子位置。
- `make_move()`：在指定坐标上落子，并返回落子是否成功。
- `has_five_in_a_row()`：判断指定坐标是否连成了五子。

主函数循环接受玩家输入并执行落子和判断胜利的逻辑，直到有一方玩家胜利。