#include stdio.h
#include stdlib.h
#include stdbool.h

void hollow_sqr(size_t height, size_t width, char c);
void solid_sqr(size_t height, size_t width, char c);

int main()
{
  size_t height, width;
  char c, buffer[5],type, *ptr;
  void (*sqr_ptr)(size_t height, size_t width, char c);

  puts("enter the height and width of the square");
  fgets(buffer, 5, stdin);
  height = strtoul(buffer, &ptr, 10);

  if(!*ptr && (ptr != buffer))
    {
      fgets(buffer, 5, stdin);
      width = strtoul(buffer, &ptr, 10);
    }
  else
    {
      puts("parse error");
      return 1;
    }

  if(!*ptr && (ptr != buffer))
    {
      puts("hollow or solid?(0 or 1)");
      type = getchar();
    }
  else
    {
      puts("parse error");
      return 1;
    }

  puts("what symbol do you want to use?");
  c = getchar();

  if(!height || !width)
    {
      puts("\nsize cannot be zero!");
      main();
    }
  else
    {
      sqr_ptr = (!type) ? hollow_sqr : solid_sqr;
      sqr_ptr(height, width, c);
    }

  getchar();
  return 0;
}

void hollow_sqr(size_t height, size_t width, char c)
{
  short i,j;
  bool endrow;

  for(i=0;i