帮忙看下这个程序怎么修改

include <stdio.h>
#include <conio.h>
#include <process.h>

int main()
{
    system("CLS");
    
    printf("hello, world!\n");
    printf("%c", 2);
    
    getch ();
    return 0;
}

while(bioskey 1 == 0)

key = bioskey(0);

switch(bioskey)
{
case UP:
    
    statements;
    
    break;
    
    case DOWN;
        
        statements;
        
        break;
        
case LEFT:
    
    statements;
    
    break;
    
case RIGHT:
    
    statements;
    
    break;
    
default:
    
    statements;
    
    break;
}