private static Set TopCountWithTiesInternal(Set InputSet, int NCount, Expression SortExpression, bool Desc)
{
List <TupleValue> TupleValues = new List <TupleValue>();
PriorityQueue queue = new PriorityQueue();
foreach (Tuple t in InputSet.Tuples)
{
double dblValue = (double)SortExpression.Calculate(t);
if (!Desc)
{
dblValue = -dblValue;
}
TupleValue tv = new TupleValue(t, dblValue);
bool bInsertTuple = false;
if (queue.Count < NCount || queue.CountWithoutTies < NCount) //short circuit on simple count... only hit CountWithTies when needed
{
bInsertTuple = true;
}
else
{
TupleValue r = (TupleValue)queue.Peek();
int cmp = tv.CompareTo(r);
if (cmp > 0)
{
//a new lower value is being added which bumps off the highest value
//if there's a tie for the highest value, bump all the ties off
while (r.CompareTo((TupleValue)queue.Peek()) == 0)
{
queue.Pop();
}
bInsertTuple = true;
}
else if (cmp == 0)
{
bInsertTuple = true;
}
}
if (bInsertTuple)
{
queue.Push(tv);
}
}
System.Collections.Generic.Stack <TupleValue> stack = new System.Collections.Generic.Stack <TupleValue>(queue.Count);
while (queue.Count > 0)
{
TupleValue tv = (TupleValue)queue.Pop();
stack.Push(tv);
}
SetBuilder sb = new SetBuilder();
while (stack.Count > 0)
{
TupleValue tv = stack.Pop();
sb.Add(tv.Tuple);
}
return(sb.ToSet());
}