Consider the following function written in the C.

int fun1(char *s)

{

   int len, c;

   char *begin, *end, temp;

   len = fun2(s);

   begin  = s;

   end    = s;

   for (c = 0; c < len - 1; c++)

      end++;

   for (c = 0; c < len/2; c++)

   {       

      temp   = *end;

      *end   = *begin;

      *begin = temp;

      begin++;

      end--;

   }

return 0;

}

int fun2(char *p)

{

   int c = 0;

   while( *(p + c) != '\0' )

      c++;

   return c;

}

The output of the above function 'fun1' on input “testbook” is