đọc file

//https://www.facebook.com/pages/C%C3%B9ng-h%E1%BB%8Dc-l%E1%BA%ADp-tr%C3%ACnh/632038696941833
void ReadFile(List &L, string path = "")
{
	fstream f;
	f.open(path, ios::out | ios::in);
	char c;
	if (f)
	{
		while (!f.eof())
		{
			f >> c;
			if (f.eof()) break;
			AddHead(L, CreateNode(c - 48));
		}
	}
	else cout << "path error\n";
	f.close();
}