[Game]Snake

实现贪食蛇的功能，具体如下：

• 每次用户能做的操作是输入对应移动的方向
• 每次只能有一个食物，被吃了之后继续随机生成
• snake吃了食物之后长度加一
• 碰到墙壁，或者自身之后游戏结束

功能很简单，实现起来也很straightforward，注意每次snake移动的时候，如果没有碰到食物，墙壁或者自身，只需要新加一个头的位置，去掉尾巴的位置，所以我们用list维护。

游戏效果如下：

代码如下：

	class Snake
	{
	public:
	Snake(int r, int c)
	{
	rows = r;
	cols = c;
	snake.push_back(0);
	used.insert(0);
	food = getFood();
	}
	void Start()
	{
	cout << "Game Start, you are at (0, 0), board: " << endl;
	print();
	while(true)
	{
	cout << "Please enter your moving direction: ";
	char c;
	cin >> c;
	while(!inputValid(c))
	{
	cout << endl;
	cout << "Please make sure your input isvalid(U/R//D/L): ";
	cin >> c;
	}
	int res = move(c);
	if(res == -1)
	{
	cout << "Game end!" << endl;
	getchar();
	return;
	}
	print();
	cout << "Current socre: " << score() << endl;
	}
	}
	private:
	int rows, cols, food;
	list<int> snake;
	unordered_set<int> used;
	vector<pair<int, int>> dirs = {{-1, 0}, {0, 1}, {1, 0}, {0, -1}};
	int move(char c)
	{
	c = toupper(c);
	int head = snake.front(), x = head / cols, y = head % cols;
	switch(c)
	{
	case 'U':
	x += dirs[0].first; y += dirs[0].second;
	break;
	case 'R':
	x += dirs[1].first; y += dirs[1].second;
	break;
	case 'D':
	x += dirs[2].first; y += dirs[2].second;
	break;
	case 'L':
	x += dirs[3].first; y += dirs[3].second;
	break;
	default:
	return -1;
	}
	if(x >= 0 && x < rows && y >= 0 && y < cols)
	{
	int tail = snake.back();
	if(x * cols + y != food)
	{
	used.erase(tail);
	snake.pop_back();
	}
	else
	food = getFood();
	if(used.find(x * cols + y) != used.end())return -1;
	snake.push_front(x * cols + y);
	used.insert(x * cols + y);
	return score();
	}
	else return -1;
	}
	void print()
	{
	for(int i = 0; i < rows; ++i)
	{
	for(int j = 0; j < cols; ++j)
	{
	int key = i * cols + j;
	if(food == key)
	cout << "#";
	else if(used.find(key) != used.end())
	cout << "*";
	else
	cout << "X";
	}
	cout << endl;
	}
	}
	int score()
	{
	return static_cast<int>(snake.size());
	}
	int getFood()
	{
	int x = rand() % (rows * cols);
	while(used.find(x) != used.end())
	x = rand() % (rows * cols);
	return x;
	}
	bool inputValid(char c)
	{
	c = toupper(c);
	switch(c)
	{
	case 'U':
	case 'R':
	case 'D':
	case 'L':
	return true;
	default:
	return false;
	}
	}
	};
	int main()
	{
	Snake snake(10, 10);
	snake.Start();
	}

view raw Snake.cpp hosted with ❤ by GitHub