C语言手把手教你实现贪吃蛇AI（上）

#ifndef SNAKE_H_ 
#define SNAKE_H_ 
#include<stdio.h> 
#include<Windows.h> //SetConsoleCursorPosition, sleep函数的头函数 
#include<time.h> //time()的头函数 
#include<malloc.h>  //malloc()的头函数 
#define N 32 //地图大小 
#define snake_mark '#'//表示蛇身 
#define food_mark '$' 
#define sleeptime 500 
 
/*表示蛇身坐标的结构体*/ 
typedef struct SNAKE{ 
  int x; //行坐标 
  int y; //列坐标 
  struct SNAKE* next; 
}snake_body, *psnake; 
extern psnake food; 
 
typedef enum Direction{ 
  U,D,L,R} direction;//蛇头的朝向 
extern direction snake_direction; 
 
void set_cursor_position(int x, int y); 
void initial_map(); 
psnake initial_snake(); 
void create_food(psnake snake,psnake food); 
void printe_map(psnake snake, psnake food); 
int is_food(psnake snake_head, psnake food); 
int is_boundary(psnake snake_head, psnake food); 
int is_snakebody(psnake snake_head, psnake food); 
psnake snake_move(psnake sanke, psnake food); 
void control_snake(); 
#endif 

#include"gluttonous.h" 
 
void set_cursor_position(int x, int y) 
{ 
  COORD coord = { x, y };//x表示列，y表示行。 
  SetConsoleCursorPosition(GetStdHandle(STD_OUTPUT_HANDLE), coord); 
} 
 
/*初始化后的地图为 N列 N/2行*/ 
/*游戏的空间为2至N+1列，1至N/2行*/ 
void initial_map() 
{ 
  int i = 0; 
   
  //打印上下边框（每个■占用一行两列） 
  for (i = 0; i<N/2+2; i++)   
  { 
    set_cursor_position(2*i, 0); 
    printf("■"); 
    set_cursor_position(2*i, N/2+1); 
    printf("■"); 
  } 
  for (i = 0; i<N/2+2; i++)  //打印左右边框  
  { 
    set_cursor_position(0, i); 
    printf("■"); 
    set_cursor_position(N+2, i); 
    printf("■"); 
  } 
} 
 
/*初始化蛇身*/ 
/*蛇身初始化坐标为（5,8）,(4,8), (3,8) */ 
psnake initial_snake() 
{ 
  int i=5;//列 
  int j = N / 4;//行 
  psnake snake = NULL, tsnake = NULL, temp = NULL; 
 
  snake = (psnake)malloc(sizeof(snake_body)); 
  (snake)->x = i; 
  (snake)->y = j; 
  (snake)->next = NULL; 
  tsnake = snake; 
 
  for (i = 4; i >2; i--) 
  { 
    temp = (psnake)malloc(sizeof(snake_body)); 
    (temp)->x = i; 
    (temp)->y = j; 
    (temp)->next = NULL; 
    (tsnake)->next = (temp); 
    (tsnake) = (tsnake)->next; 
  } 
  return snake; 
} 
 
void create_food(psnake snake, psnake food) 
{ 
  static int i=1; 
  psnake head = snake; 
  srand((unsigned)time(NULL)); 
  food->x = rand() % N + 2; 
  food->y = rand() % (N/2) + 1; 
 
  //检查食物是否和蛇身重回 
  while (head) 
  { 
    if (head->x == food->x && head->y == food->y) 
    { 
      free(food); 
      food = NULL; 
      create_food(snake,food); 
    } 
    else 
    { 
      head = head->next; 
    } 
  } 
} 
 
void printe_map(psnake snake, psnake food) 
{ 
  psnake temp=snake; 
  while (temp) 
  { 
    set_cursor_position(temp->x, temp->y); 
    printf("%c",snake_mark); 
    temp = temp->next; 
  } 
  if (food) 
    set_cursor_position(food->x,food->y ); 
  printf("%c",food_mark); 
  set_cursor_position(0, N/2+2); 
} 
 
//判断是否吃到食物，吃到食物返回 1，否则返回 0； 
int is_food(psnake snake_head, psnake food) 
{ 
  if (snake_head->x == food->x && snake_head->y == food->y) 
    return 1; 
  return 0; 
} 
 
//判断是否撞到墙，撞到墙返回 1，否则返回 0； 
int is_boundary(psnake snake_head) 
{ 
  if (snake_head->y <= 0 || snake_head->y >= N / 2 + 1 || snake_head->x <= 1 || snake_head->x >= N + 1) 
    return 1; 
  return 0; 
} 
 
//判断是否撞到自己，撞到自己返回 1，否则返回 0； 
int is_snakebody(psnake snake_head) 
{ 
  psnake temp=snake_head->next; 
  while (temp) 
  { 
    if (snake_head->x == temp->x && snake_head->y == temp->y) 
      return 1; 
    else 
      temp = temp->next; 
  } 
  return 0; 
} 
 
//将蛇身移动到合适的位置，并打印出来 
psnake snake_move(psnake snake, psnake food) 
{ 
  psnake snake_head = (psnake)malloc(sizeof(snake_body)); 
  if (snake_direction == U) 
  { 
    snake_head->y = snake->y-1; 
    snake_head->x = snake->x; 
    snake_head->next = snake; 
  } 
  else if (snake_direction == D) 
  { 
    snake_head->y = snake->y + 1; 
    snake_head->x = snake->x; 
    snake_head->next = snake; 
  } 
  else if (snake_direction == L) 
  { 
    snake_head->y = snake->y; 
    snake_head->x = snake->x - 1; 
    snake_head->next = snake; 
  } 
  else if (snake_direction == R) 
  { 
    snake_head->y = snake->y; 
    snake_head->x = snake->x + 1; 
    snake_head->next = snake; 
  } 
 
  if (is_food(snake_head, food))//如果是食物 
  { 
    create_food(snake_head, food); 
    printe_map(snake_head, food); 
  } 
  else if (is_boundary(snake_head) == 0 && is_snakebody(snake_head) == 0)//不是食物，不是边界，也不是蛇身 
  { 
    psnake temp = snake_head; 
    while (temp->next->next)//寻找蛇尾 
    { 
      temp = temp->next; 
    } 
    set_cursor_position(temp->next->x, temp->next->y); 
    printf(" ");//把蛇尾用空格消掉 
    free(temp->next);//释放蛇尾的内存空间 
    temp->next = NULL;//将temp的next置成NULL 
    printe_map(snake_head, food); 
  } 
  else 
  { 
    free(snake_head); 
    snake_head = NULL; 
  } 
  return snake_head; 
} 
 
void control_snake() 
{ 
  if (GetAsyncKeyState(VK_UP) && snake_direction != D) 
  { 
    snake_direction = U; 
  } 
  else if (GetAsyncKeyState(VK_DOWN) && snake_direction != U) 
  { 
    snake_direction = D; 
  } 
  else if (GetAsyncKeyState(VK_LEFT) && snake_direction != R) 
  { 
    snake_direction = L; 
  } 
  else if (GetAsyncKeyState(VK_RIGHT) && snake_direction != L) 
  { 
    snake_direction = R; 
  } 
}

#include"gluttonous.h" 
direction snake_direction; 
psnake food; 
 
int main(void) 
{ 
  psnake snake; 
 
  initial_map(); 
  snake=initial_snake(); 
  food = (psnake)malloc(sizeof(snake_body)); 
  food->next = NULL; 
  create_food(snake, food); 
  printe_map(snake, food); 
  snake_direction = R; 
  while (1) 
  { 
    Sleep(sleeptime); 
    control_snake(); 
    snake=snake_move(snake, food); 
  } 
  return 0; 
}