private Comparable RightChild(Comparable X)
{
int idx = RightChildIndex(X) - 1;
if (idx < ImplicitHeap.Count)
{
return((Comparable)ImplicitHeap[idx]);
}
else
{
return(null);
}
}
private Comparable Parent(Comparable X)
{
int idx = ParentIndex(X) - 1;
if (idx > -1)
{
return((Comparable)ImplicitHeap[idx]);
}
else
{
return(null);
}
}
public void Insert(Comparable X)
{
//for (int i = 0; i < ImplicitHeap.Count; i++)
//{
// if (ImplicitHeap[i] == X)
// {
// BasicConsole.Write(Name);
// BasicConsole.Write(" - ");
// BasicConsole.WriteLine("Priority queue : Error! Attempted to re-insert item.");
// return;
// }
//}
X.Position = ImplicitHeap.Count + 1;
ImplicitHeap.Add((FOS_System.Object)X);
DecreaseKey(X, X.Key);
}
public void DecreaseKey(Comparable X, int NewKey)
{
if (NewKey > X.Key)
{
ExceptionMethods.Throw(new Exceptions.ArgumentException("New key is larger than old key!"));
}
X.Key = NewKey;
Comparable parent = Parent(X);
while (parent != null &&
X.Key < parent.Key)
{
Swap(parent, X);
parent = Parent(X);
}
}
public void DecreaseKey(Comparable X, int NewKey)
{
if (NewKey > X.Key)
{
ExceptionMethods.Throw(new Exceptions.ArgumentException("New key is larger than old key!"));
}
X.Key = NewKey;
Comparable parent = Parent(X);
while (parent != null &&
X.Key < parent.Key)
{
Swap(parent, X);
parent = Parent(X);
}
}
private int RightChildIndex(Comparable X)
{
return((X.Position * 2) + 1);
}
private int LeftChildIndex(Comparable X)
{
return(X.Position * 2);
}
public bool Insert(Comparable X)
{
//for (int i = 0; i < ImplicitHeap.Count; i++)
//{
// if (ImplicitHeap[i] == X)
// {
// BasicConsole.Write(Name);
// BasicConsole.Write(" - ");
// BasicConsole.WriteLine("Priority queue : Error! Attempted to re-insert item.");
// return false;
// }
//}
X.Position = ImplicitHeap.Count + 1;
ImplicitHeap.Add((FOS_System.Object)X);
DecreaseKey(X, X.Key);
return true;
}
private int RightChildIndex(Comparable X)
{
return (X.Position * 2) + 1;
}
private int ParentIndex(Comparable X)
{
if (X.Position > 1)
{
return X.Position / 2;
}
return 0;
}
private Comparable RightChild(Comparable X)
{
int idx = RightChildIndex(X)-1;
if (idx < ImplicitHeap.Count)
{
return (Comparable)ImplicitHeap[idx];
}
else
{
return null;
}
}
private Comparable Parent(Comparable X)
{
int idx = ParentIndex(X)-1;
if (idx > -1)
{
return (Comparable)ImplicitHeap[idx];
}
else
{
return null;
}
}
private void Swap(Comparable X, Comparable Y, bool print = false)
{
int tempPos = X.Position;
X.Position = Y.Position;
Y.Position = tempPos;
ImplicitHeap[X.Position - 1] = (FOS_System.Object)X;
ImplicitHeap[Y.Position - 1] = (FOS_System.Object)Y;
}
private void Rebalance(Comparable Y)
{
//BasicConsole.WriteLine("Rebalance (1)");
Comparable ALeftChild = LeftChild(Y);
Comparable ARightChild = RightChild(Y);
while ((ALeftChild != null && Y.Key > ALeftChild.Key) ||
(ARightChild != null && Y.Key > ARightChild.Key))
{
//BasicConsole.WriteLine("Rebalance (2)");
if (ALeftChild != null && Y.Key > ALeftChild.Key)
{
if (ARightChild != null && ARightChild.Key < ALeftChild.Key)
{
Swap(ARightChild, Y);
}
else
{
Swap(ALeftChild, Y);
}
}
else if (ARightChild != null && Y.Key > ARightChild.Key)
{
Swap(ARightChild, Y);
}
ALeftChild = LeftChild(Y);
ARightChild = RightChild(Y);
}
}
public void Delete(Comparable X)
{
//BasicConsole.WriteLine("Deleting");
//bool OK = false;
//for (int i = 0; i < ImplicitHeap.Count; i++)
//{
// if (ImplicitHeap[i] == X)
// {
// OK = true;
// break;
// }
//}
//if (!OK)
//{
// BasicConsole.WriteLine("Deleting when not present.");
//}
if (X.Position <= 0 || X.Position > ImplicitHeap.Count || ImplicitHeap[X.Position - 1] != X)
{
//BasicConsole.WriteLine("No delete");
return;
}
//BasicConsole.WriteLine("Will delete");
if (ImplicitHeap.Count > 1)
{
//BasicConsole.WriteLine("Using last item");
Comparable Y = (Comparable)ImplicitHeap.Last();
if (X != Y)
{
//BasicConsole.WriteLine("X not equal to Y");
//BasicConsole.WriteLine("Removing Y");
ImplicitHeap.RemoveAt(Y.Position - 1);
//BasicConsole.WriteLine("Setting Y position");
Y.Position = X.Position;
//BasicConsole.WriteLine("Setting Y in array");
ImplicitHeap[Y.Position - 1] = (FOS_System.Object)Y;
//BasicConsole.WriteLine("Rebalancing");
Rebalance(Y);
}
else
{
//BasicConsole.WriteLine("X is Y, removing X");
ImplicitHeap.RemoveAt(X.Position - 1);
}
}
else
{
//BasicConsole.WriteLine("Removing at index 0");
ImplicitHeap.RemoveAt(0);
}
//BasicConsole.WriteLine("Reset position");
X.Position = 0;
}
public virtual int Compare(Comparable x, Comparable y)
{
return x.Key < y.Key ? -1 : x.Key == y.Key ? 0 : 1;
}
public virtual int Compare(Comparable x, Comparable y)
{
return(x.Key < y.Key ? -1 : x.Key == y.Key ? 0 : 1);
}
private int LeftChildIndex(Comparable X)
{
return X.Position * 2;
}
