请补全该六子棋博弈树代码，使其最终输出结果为下两步棋的坐标：#define max_depth 4 typedef struct { int x,y; }Move;//棋的坐标 typedef struct { int startX,startY,resultX,resultY; }res; int build_game_tree(GameState* state, int depth, Move *best_move) { int max_value=-100000; int min_value=100000; if (depth == 0) return; for(int i=0;i<GRIDSIZE;i++) { for(int j=0;j<GRIDSIZE;j++) { if(board[i][j]==0) { int value=evaluate();//计算该位置的评估函数 if(value>max_value) { max_value=value; } if(depth==max_depth) { best_move->x=i; best_move->y=j; board[i][j]=1; } res.resultX=i; res.resultY=j; } } } build_game_tree(GameState* state, int depth, Move *best_move) }

#define max_depth 4

typedef struct {
int x,y;
}Move;//棋的坐标

typedef struct {
int startX,startY,resultX,resultY;
}res;

int build_game_tree(GameState* state, int depth, Move *best_move)
{
int max_value=-100000;
int min_value=100000;

if (depth == 0)
return evaluate(); // 返回当前局面的评估值

for(int i=0;i<GRIDSIZE;i++)
{
for(int j=0;j<GRIDSIZE;j++)
{
if(board[i][j]==0)
{
board[i][j]=1; // 假设此处下一步是我方棋子
int value=build_game_tree(state, depth-1, best_move);
board[i][j]=0; // 恢复现场

if(value>max_value)
{
max_value=value;
if(depth==max_depth)
{
best_move->x=i;
best_move->y=j;
}
}

if(value<min_value)
{
min_value=value;
}

res.resultX=i;
res.resultY=j;
}
}
}

if (depth == max_depth) {
printf("下一步应该落子的位置：(%d,%d)\n", best_move->x, best_move->y);
}

return (state->player == 1) ? max_value : min_value; // 返回当前局面的最优值
}