Re: Shift elements of an array

On Sun, 06 Oct 2013 18:59:06 +0200, Rosario1903 wrote:
the last version for this exercise.

#include <iostream>
#include <cstdlib>

using namespace std;
#define u32 unsigned
#define u8 unsigned char

class myarray{
public:
~myarray(){free(arr);}
 myarray(){arr=(u8*) malloc(15);
           if(arr==0) exit(-1);
           s=15;
          }

 myarray(u32 c)
          {if(c>0xFFFF) exit(-1);
           arr=(u8*)malloc(c);
           if(arr==0) exit(-1);
           s=c;
          }

 myarray(char* c)
          {u32 v, i;
           if(c==0)
                {v=1;}
           else {v=strlen(c)+1;}
           arr=(u8*)malloc(v);
           if(arr==0) exit(-1);
           if(v==1) *arr=0;
           else {for(i=0; i<v ; ++i)
                  {arr[i]=c[i];
                   if(c[i]==0) break;
                  }
                 for(; i<v;++i)
                   arr[i]=0;
                }
           s=v;
          }

 friend ostream& operator<<(ostream& os, myarray& ma)
 {u32 i;
  if(ma.s!=0)
    {for(i=0; i<ma.s-1; ++i)
             os<<ma.arr[i];
     return os<<ma.arr[i];
    }
  else return os;
 }

 u32 shiftd(myarray& ma, u32 pos)
 {u32 i, j;
  if(s<ma.s)
      {free(arr);
       arr=(u8*)malloc(ma.s);
       if(arr==0) exit(-1);
       s=ma.s;
      }
  if(pos>=ma.s)
       {for(i=0;i<s; ++i) arr[i]=0;}
  else {/* 0 1 2 3 4 5 6 */
        /* | shiftd 3*/
        for(j=pos, i=0; j<ma.s; ++j,++i)
            arr[i]=ma.arr[j];
        for(;i<s;++i)
            arr[i]=0;
       }
  return 1;
 }

u32 s;
u8 *arr;
};

int main(void)
{myarray v("this and that "), ma;
 u32 i;

 cout<<"at start v=["<<v <<"]\n";
 ma.shiftd(v, 3);
 cout<<"at end ma=["<<ma<<"]\n";

 for(i=0;i<12;++i)
    {ma.shiftd(ma, 1);
     cout<<"at end ma=["<<ma<<"]\n";
    }

 return 0;
}

---------------
at start v=[this and that ]
at end ma=[s and that ]
at end ma=[ and that ]
at end ma=[and that ]
at end ma=[nd that ]
at end ma=[d that ]
at end ma=[ that ]
at end ma=[that ]
at end ma=[hat ]
at end ma=[at ]
at end ma=[t ]
at end ma=[ ]
at end ma=[ ]
at end ma=[ ]