贪吃蛇的设计(1)(无界面版本)

[0]移动模块:贪吃蛇移动的方向(上,下,左,右)，注意不能朝反方向进行移动.每次移动需要检测是否撞到边界或者吃到自己。每一个节点都往前进一步.

/******返回false代表失败*************/
bool Snake::move(string ms)
{
/************处理头部的坐标变换************/
auto iter = data.begin();
position last = (*iter);//记录上一个节点的坐标
auto test_x = iter->x + direction[ms].x;
auto test_y = iter->y + direction[ms].y;
/*判断是非朝反方向走*/
if (data[1].x == test_x&&data[1].y == test_y)
return true;//朝反方向
else if (!(isgood(test_x) && isgood(test_y)))
return false;//撞墙
else //新节点正常
*iter = position(test_x, test_y);

auto original_x =iter->x, original_y = iter->y;
/*************新的首节点不能和剩下的节点冲突*************************/
while (++iter != data.end())
{
position temp = *iter;
*iter = last;//这个节点的坐标变成上一个节点
last = temp;
if (original_x == iter->x && original_y == iter->y)//节点冲突,结束
break;
}
return iter==data.end();
}

[1]类的设计:

class position
{
public:
position() :x(0), y(0){}
position(int a, int b) :x(a), y(b){}
int x;
int y;
};
class Snake
{

public:
/**********构造函数**********/
Snake(int n) :N(n){}
bool move(string);
void display();
inline void add_node(int x, int y){ data.push_back(position(x, y)); }

private:
const int N;//活动区域的大小: N*N
vector<position> data;
static map<string, position> direction;
inline bool isgood(int x){ return (x != -1 && x != N); }

};

[2]：显示,没有界面设计的情况下就只能用控制台显示了,首先进行对节点按坐标（先排横坐标,再排纵坐标）排序,然后用*显示出来：

bool isless(position a, position b){
if (a.x < b.x)
return true;
else if (a.x > b.x)
return false;
else return a.y < b.y;
}
void Snake::display()
{

auto displayer_data = data;
sort(displayer_data.begin(), displayer_data.end(), isless);
auto last = displayer_data.begin();
cout << string(N - 1, '=') << string(last->x,'\n');
cout << string(last->y, ' ')<<"*";//输出第一个
int count = 0;
for (auto beg = displayer_data.begin()+1; beg != displayer_data.end(); ++beg,++last)
{

if (beg->x != last->x)
cout << endl << string(beg->y, ' ')<<"*";
else
cout << string(beg->y - last->y-1, ' ')<<"*";
}
cout << string(N - 1 - last->x, '\n') << string(N - 1, '=');
}

[3]：main函数:每隔3个移动就增加一个尾部节点.

int main()
{
Snake game(25);
for (int i = 0; i != 7; ++i)
game.add_node(7, i);
string ms;
int count = 0;
while (cin >> ms&&game.move(ms))
{
game.display();
if (!(++count % 3))
game.add_node(game.lastnode.x,game.lastnode.y);
}
cout << "game over\n";
return 0;
}