用c语言写一个六子棋博弈树

好的，下面是一个简单的六子棋博弈树的C语言实现：

#include <stdio.h>
#define BOARD_SIZE 6

// 定义棋盘的结构体
struct board {
    int cells[BOARD_SIZE][BOARD_SIZE];
};

// 初始化棋盘
void init_board(struct board *b) {
    int i, j;
    for (i = 0; i < BOARD_SIZE; i++) {
        for (j = 0; j < BOARD_SIZE; j++) {
            b->cells[i][j] = 0;
        }
    }
}

// 打印棋盘
void print_board(struct board *b) {
    int i, j;
    for (i = 0; i < BOARD_SIZE; i++) {
        for (j = 0; j < BOARD_SIZE; j++) {
            printf("%c ", (b->cells[i][j] == 0) ? '.' : ((b->cells[i][j] == 1) ? 'O' : 'X'));
        }
        printf("\n");
    }
}

// 判断胜负
int check_win(struct board *b, int player) {
    int i, j, k;
    for (i = 0; i < BOARD_SIZE; i++) {
        for (j = 0; j < BOARD_SIZE; j++) {
            if (b->cells[i][j] == player) {
                // 水平
                for (k = 0; k < 6 && i + k < BOARD_SIZE && b->cells[i+k][j] == player; k++);
                if (k == 6) return 1;
                // 垂直
                for (k = 0; k < 6 && j + k < BOARD_SIZE && b->cells[i][j+k] == player; k++);
                if (k == 6) return 1;
                // 左上到右下
                for (k = 0; k < 6 && i + k < BOARD_SIZE && j + k < BOARD_SIZE && b->cells[i+k][j+k] == player; k++);
                if (k == 6) return 1;
                // 左下到右上
                for (k = 0; k < 6 && i - k >= 0 && j + k < BOARD_SIZE && b->cells[i-k][j+k] == player; k++);
                if (k == 6) return 1;
            }
        }
    }
    return 0;
}

// 构建博弈树
int build_tree(struct board *b, int player, int depth) {
    int i, j, k, score, max_score = -1000000, min_score = 1000000;
    struct board new_b;
    if (depth == 0 || check_win(b, 1) || check_win(b, 2)) {
        return (player == 1) ? check_win(b, 1) - check_win(b, 2) : check_win(b, 2) - check_win(b, 1);
    }
    for (i = 0; i < BOARD_SIZE; i++) {
        for (j = 0; j < BOARD_SIZE; j++) {
            if (b->cells[i][j] == 0) {
                new_b = *b;
                new_b.cells[i][j] = player;
                score = build_tree(&new_b, (player == 1) ? 2 : 1, depth - 1);
                if (player == 1) {
                    if (score > max_score) max_score = score;
                } else {
                    if (score < min_score) min_score = score;
                }
            }
        }
    }
    return (player == 1) ? max_score : min_score;
}

// 程序入口
int main() {
    struct board b;
    int i, j, score, max_score = -1000000, x, y;
    init_board(&b);
    print_board(&b);
    for (i = 0; i < BOARD_SIZE; i++) {
        for (j = 0; j < BOARD_SIZE; j++) {
            if (b.cells[i][j] == 0) {
                struct board new_b = b;
                new_b.cells[i][j] = 1;
                score = build_tree(&new_b, 2, 3);
                if (score > max_score) {
                    max_score = score;
                    x = i;
                    y = j;
                }
            }
        }
    }
    b.cells[x][y] = 1;
    printf("Computer: (%d, %d)\n", x, y);
    print_board(&b);
    return 0;
}

这个程序实现了一个简单的六子棋博弈树，通过构建博弈树来计算每个可落子位置的得分，并选择得分最高的位置进行落子。其中 `build_tree` 函数递归地构建博弈树，并返回当前局面下最大/最小得分。