poj 1049 Microprocessor Simulation

poj 1049 Microprocessor Simulation

简单的模拟，读懂了题就会做了

#include  < stdio.h >

char  hax[ 17 ] = " 0123456789ABCDEF " ;
char  ans[ 256 ];

int  main()
{
     char  a, b;
     while  ( 1 )
    {
         int  i;
         for  ( i  =   0  ; i  <   256  ; i ++  )
        {
             if ( EOF  ==  scanf( " %c " , ans + i) )  return   0 ;
            ans[i] -= ( ans[i]  >   ' 9 '   ?   55  :  48  );
        }
        getchar();
         if  ( ans[ 0 ]  ==   8  )  break ;
         int  num  =   0 , flag =   1 ;
         char  t;
         while  (flag)
        {
             switch (ans[num ++ ])
            {
                 case   0 :
                    a =  ans[ (ans[num] << 4 ) + ans[num + 1 ] ];
                    num += 2 ;
                     break ;
                 case   1 :
                    ans[ (ans[num] << 4 ) + ans[num + 1 ] ] = (a &= 15 );
                    num += 2 ;
                     break ;
                 case   2 :
                    t =  a;
                    a =  b;
                    b =  t;
                     break ;
                 case   3 :
                    a += b;
                    b = a >> 4 ;
                     break ;
                 case   4 :
                    a ++ ;
                     break ;
                 case   5 :
                    a -- ;
                     break ;
                 case   6 :
                     if  ( a & 15  )
                    {
                        num += 2 ;
                         break ;
                    }
                 case   7 :
                    num = (ans[num] << 4 ) + ans[num + 1 ];
                     break ;
                 case   8 :
                    flag = 0 ;
                     break ;
                 default :
                     break ;
            }
        }
         for  ( i  =   0  ; i  <   256  ; i ++  )
            printf( " %c " , hax[ans[i]]);
        putchar( 10 );
    }
     return   0 ;
}