Re: Shift elements of an array

Alf wrote:


one other error
there is no need of this ungly word "const"


#include <iostream>
#include <cstdlib>

using namespace std;

#define u32 unsigned
#define u8 unsigned char
#define F for
#define R return

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 {F(i=0; i<v ; ++i)
                  {arr[i]=c[i];
                   if(c[i]==0) break;
                  }
                 F(; i<v;++i)
                   arr[i]=0;
                }
           s=v;
          }

 myarray& operator=(const myarray& r)
/* here i had to use the ugnly word "const" */
 {u32 i;

  if(s<r.s)
     {free(arr);
      arr=(u8*) malloc(r.s);
      if(arr==0) exit(-1);
      s=r.s;
     }
  F(i=0; i<r.s; ++i)
       arr[i]=r.arr[i];
  R *this;
 }

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

 void 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)
       {F(i=0;i<s; ++i) arr[i]=0;}
  else {/* 0 1 2 3 4 5 6 */
        /* | shiftd 3*/
        F(j=pos, i=0; j<ma.s; ++j,++i)
            arr[i]=ma.arr[j];
        F(;i<s;++i)
            arr[i]=0;
       }
 }

u32 s;
u8 *arr;
};

myarray *bi[50]={0};
u32 index=0;

void fill_bi(myarray* a)
{if(index==49) exit(-1);
 bi[index]=a;
 ++index;
}

void free_bi(void)
{myarray *a;
 u32 i;

 if(index!=0)
   {F(i=index-1; ; --i)
     {a=bi[i];
      free(a->arr);
      free(a);
      bi[i]=0;
      if(i==0) break;
     }
   }
 index=0;
}

myarray& f(void)
{myarray a("1 2 3 4"), *b;

 b=(myarray*)malloc(sizeof *b);
 if(b==0) exit(-1);
 b->arr=(u8*)malloc(15);
 if(b->arr==0) exit(-1);
 b->s=15;
 fill_bi(b);

 *b=a;
 R *b;
}

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

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

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

 b=v;
 cout<<"b="<<b<<"\n";
 b=f();
 free_bi();

 cout<<"b="<<b<<"\n";
 R 0;
}