用C语言写一个返回值为落子坐标的六子棋博弈的alpha-beta剪枝算法

以下是一个简单的六子棋博弈的alpha-beta剪枝算法示例：

#include <stdio.h>
#include <stdlib.h>

#define BOARD_SIZE 6
#define MAX_DEPTH 4

int board[BOARD_SIZE][BOARD_SIZE];

int get_score(int player) {
    int score = 0;
    // 计算当前玩家得分
    return score;
}

int evaluate() {
    int score1 = get_score(1);
    int score2 = get_score(2);
    return score1 - score2; // 返回当前局面的分数
}

int is_full() {
    int i, j;
    for (i = 0; i < BOARD_SIZE; i++) {
        for (j = 0; j < BOARD_SIZE; j++) {
            if (board[i][j] == 0) {
                return 0;
            }
        }
    }
    return 1;
}

int is_gameover() {
    // 检查是否有一方获胜或者棋盘已满
    return 0;
}

int max_value(int alpha, int beta, int depth) {
    if (depth == MAX_DEPTH || is_gameover()) {
        return evaluate();
    }
    int i, j, score, max_score = -1000000;
    for (i = 0; i < BOARD_SIZE; i++) {
        for (j = 0; j < BOARD_SIZE; j++) {
            if (board[i][j] == 0) {
                board[i][j] = 1;
                score = min_value(alpha, beta, depth + 1);
                board[i][j] = 0;
                if (score > max_score) {
                    max_score = score;
                }
                if (max_score >= beta) {
                    return max_score;
                }
                if (max_score > alpha) {
                    alpha = max_score;
                }
            }
        }
    }
    return max_score;
}

int min_value(int alpha, int beta, int depth) {
    if (depth == MAX_DEPTH || is_gameover()) {
        return evaluate();
    }
    int i, j, score, min_score = 1000000;
    for (i = 0; i < BOARD_SIZE; i++) {
        for (j = 0; j < BOARD_SIZE; j++) {
            if (board[i][j] == 0) {
                board[i][j] = 2;
                score = max_value(alpha, beta, depth + 1);
                board[i][j] = 0;
                if (score < min_score) {
                    min_score = score;
                }
                if (min_score <= alpha) {
                    return min_score;
                }
                if (min_score < beta) {
                    beta = min_score;
                }
            }
        }
    }
    return min_score;
}

void alphabeta(int *row, int *col) {
    int i, j, score, max_score = -1000000;
    *row = -1;
    *col = -1;
    for (i = 0; i < BOARD_SIZE; i++) {
        for (j = 0; j < BOARD_SIZE; j++) {
            if (board[i][j] == 0) {
                board[i][j] = 1;
                score = min_value(-1000000, 1000000, 1);
                board[i][j] = 0;
                if (score > max_score) {
                    max_score = score;
                    *row = i;
                    *col = j;
                }
            }
        }
    }
}

int main() {
    int i, j, row, col;
    while (!is_gameover()) {
        alphabeta(&row, &col);
        board[row][col] = 1;
        // AI 落子
        // 玩家落子
    }
    return 0;
}

该算法通过递归搜索所有可能的落子位置，同时利用alpha-beta剪枝对搜索树进行剪枝，以提高算法效率。具体实现中，`max_value`函数表示AI的决策，`min_value`函数表示玩家的决策，`evaluate`函数计算当前局面的分数，`alphabeta`函数返回AI的落子位置。