贪吃蛇

#include<bits/stdc++.h>
#include <conio.h>
#include <windows.h>
#include <thread>
#include <chrono>
#define zxb(VK_NONAME) ((GetAsyncKeyState(VK_NONAME) & 0x8000) ? 1:0)
using namespace std;
void hide(){
	CONSOLE_CURSOR_INFO cursor_info={1,0};
	SetConsoleCursorInfo(GetStdHandle(STD_OUTPUT_HANDLE),&cursor_info);
}
void gotoxy(int x,int y){
	COORD pos={(SHORT)x,(SHORT)y};
	SetConsoleCursorPosition(GetStdHandle(STD_OUTPUT_HANDLE),pos);
}
const int N=20;
int x=N/2,y=N/2;
queue<pair<int,int> > q;
int a[N+10][N+10];
void update(){
	int cnt=rand()%4;
	while(cnt--){
		int xx=rand()%(N+1),yy=rand()%(N+1);
		while(a[xx][yy]){
			xx=rand()%(N+1),yy=rand()%(N+1);
		}
		a[xx][yy]=2;
		gotoxy(yy,xx);
		cout<<'@';
	}
}
void del(){
	auto u=q.front();
	q.pop();
	a[u.first][u.second]=0;
	gotoxy(u.second,u.first);
	cout<<'.';
}
void move_down(){
	if(x>=N) return ;
	++x;
	if(a[x][y]!=2) del();
	else update();
	a[x][y]=1;
	gotoxy(y,x);
	cout<<'x';
	q.push({x,y});
}
void move_l(){
	if(y<=0) return ;
	--y;
	if(a[x][y]!=2) del();
	else update();
	a[x][y]=1;
	gotoxy(y,x);
	cout<<'x';
	q.push({x,y});
}
void move_r(){
	if(y>=N) return ;
	++y;
	if(a[x][y]!=2) del();
	else update();
	a[x][y]=1;
	gotoxy(y,x);
	cout<<'x';
	q.push({x,y});
}
void move_up(){
	if(x<=0) return ;
	--x;
	if(a[x][y]!=2) del();
	else update();
	a[x][y]=1;
	gotoxy(y,x);
	cout<<'x';
	q.push({x,y});
}
void print(){
	gotoxy(0,0);
    for(int i=0;i<=N;i++){
        for(int j=0;j<=N;j++){
        	if(a[i][j]==0){
        		cout<<'.';
			}else if(a[i][j]==1){
				cout<<'x';
			}else{
				cout<<'@';
			}
        }
        cout<<'\n';
    }
    cout<<"Use W,A,S,D to move. Press 'q' to quit."<<'\n';
}
bool flag=1;
int main(){
	srand(time(0));hide();
	a[x][y]=1;
	q.push({x,y});
	update();
	print();
	while(flag){
		while(1){
			if(zxb('Q')){ flag=0;break;}
			if(zxb('W')){ move_up();break;}
			if(zxb('A')){ move_l();break;}
			if(zxb('S')){ move_down();break;}
			if(zxb('D')){ move_r();break;}
		}
	    this_thread::sleep_for(chrono::milliseconds(50));
	}
	return 0;
}