typedef struct Snakes
{
	int x;
	int y;
	struct Snakes *next;
}snake;
 
snake *head,*tail;
 
struct Food
{
	int x;
	int y;
}food;

void creatgraph()             
{
	int i;
	for (i = 0; i<58; i += 2)//打印上下邊框
	{
		gotoprint(i, 0);
		gotoprint(i, 26);
	}
	for (i = 1; i < 26; i++)
	{
		gotoprint(0, i);
		gotoprint(56, i);
	}
	head = (snake*)malloc(sizeof(snake));
	head->x = 16;
	head->y = 15;
	//gotoprint(head->x, head->y);
	tail = (snake*)malloc(sizeof(snake));
	snake *p = (snake*)malloc(sizeof(snake));
	snake *q = (snake*)malloc(sizeof(snake));
	p->x = 16;
	p->y = 16;
	q->x = 16;
	q->y = 17;
	head->next = p;
	p->next = q;
	q->next = tail;
	//gotoprint(p->x, p->y);
	//gotoprint(q->x, q->y);
	tail->next = NULL;
	tail->x = 4;
	tail->y = 2;	
}
 
void gotoxy(int x, int y)
{
	COORD pos;
	HANDLE hOutput;
	pos.X = x;
	pos.Y = y;
	hOutput = GetStdHandle(STD_OUTPUT_HANDLE);
	SetConsoleCursorPosition(hOutput, pos);
}
 
void gotoprint(int x, int y)
{
	gotoxy(x, y);
	printf("■");
}
 
void gotodelete(int x, int y)
{
	gotoxy(x, y);
	printf("  ");
}

void creatfood()
{
	srand((int)time(NULL));
	lable:
	food.y = rand() % (25 - 1 + 1) + 1;
	food.x = rand() % (54 - 2 + 1) + 2;
	if (food.x % 2 != 0)
	{
		food.x = food.x+1;
	}
	snake *judge = head;
	while (1)  
	{
		if (judge->next == NULL) break;
		if (food.x == judge->x&&food.y == judge->y)
		{
			goto lable;
		}
		judge = judge->next;
	}
	gotoxy(food.x, food.y);
	printf("⊙");
}

int ClickControl()
{
	char c;
	while (1)
	{
		if (Judge()==0) return 0;
		if (_kbhit())
		{
			click = _getch();
		}
		MovingBody();
		Eating();
	}
	return 1;
}

void MovingBody()
{
	int count = 0;
	int a = head->x, b = head->y;
	snake *p = head;
	while (1)
	{
		if (p->next == NULL) break;
		gotodelete(p->x, p->y);
		count++;
		p = p->next;
	}
	switch (click)
	{
		case up:
			head->y -= 1;
			ChangeBody(a,b);
			break;
		case down:
			head->y += 1;
			ChangeBody(a,b);
			break;
		case left:
			head->x -= 2;
			ChangeBody(a,b);
			break;
		case right:
			head->x += 2;
			ChangeBody(a,b);
			break;
		case stop:
			_getch();
			break;
	}
	p = head;
	while (1)
	{
		if (p->next == NULL) break;
		gotoprint(p->x, p->y);
		p = p->next;
	}
	p = head;
	gotoxy(0, 28);
	if (count <= 10) speed = 150;
	else if (count > 10 && count <= 20) speed = 100;
	else if (count > 20 && count <= 40) speed = 50;
	else speed = 10;
	Sleep(speed);
}

void ChangeBody(int a,int b)
{
	snake *p = head->next;
	int mid1, mid2,_mid1,_mid2;
	mid1 = p->x;
	mid2 = p->y;
	while (1)
	{
		if (p->next->next == NULL) break;
		
		_mid1 = p->next->x;
		_mid2 = p->next->y;
		p->next->x = mid1;
		p->next->y = mid2;
		mid1 = _mid1;
		mid2 = _mid2; 
		p = p->next;
	}
	p = head->next;
	{
		p->x = a;
		p->y = b;
	}
}