private string _Cash(int value)
{
var alreadyCached = new List <Tuple <int, int> >();
var result = _handler.Cash(alreadyCached, value);
var toCash = result.Item1;
var remain = result.Item2;
return(remain == 0 ? GetCashedBanknotes(toCash) : "Sorry, dude, we can't cash it. Too bad");
}
public virtual Tuple <List <Tuple <int, int> >, int> Cash(List <Tuple <int, int> > alreadyCached, int value)
{
var banknoteCount = value / BanknoteValue;
var remain = value - banknoteCount * BanknoteValue;
alreadyCached.Add(Tuple.Create(BanknoteValue, banknoteCount));
return(_nextHandler == null
? Tuple.Create(alreadyCached, remain)
: _nextHandler.Cash(alreadyCached, remain));
}