/// <summary>
/// Adds a new patient to the priorityQueue and calls OrderDowntoUp()
/// </summary>
/// <param name="key"></param> represents the node's key.
/// <param name="date"></param> represents date as a secondary priority criteria.
/// <param name="patient"></param> represents the value that's been inserted to the queue
/// <param name="priority"></param> represents the patient's priority.
public void AddPatient(string key, DateTime date, T patient, int priority)
{
var newNode = new PQNode <T>(key, date, patient, priority);
if (IsEmpty())
{
Root = newNode;
PatientsNumber = 1;
}
else
{
PatientsNumber++;
var NewNodeFather = SearchLastNode(Root, 1);
if (NewNodeFather.LeftSon != null)
{
NewNodeFather.RightSon = newNode;
newNode.Father = NewNodeFather;
OrderDowntoUp(newNode);
}
else
{
NewNodeFather.LeftSon = newNode;
newNode.Father = NewNodeFather;
OrderDowntoUp(newNode);
}
}
}
/// <summary>
/// Remove the first node from the Priority Queue.
/// </summary>
/// <returns></returns>
public PQNode <T> GetFirst()
{
if (Root == null)
{
return(null);
}
PQNode <T> LastNode = SearchLastNode(Root, 1);
PQNode <T> FirstNode = (PQNode <T>)Root.Clone();
var LastNodeCopy = (PQNode <T>)LastNode.Clone();
Root.Key = LastNodeCopy.Key;
Root.Priority = LastNodeCopy.Priority;
Root.Patient = LastNodeCopy.Patient;
Root.DatePriority = LastNodeCopy.DatePriority;
if (LastNode.Father == null)
{
Root = null;
PatientsNumber--;
return(LastNode);
}
else
{
if (LastNode.Father.LeftSon == LastNode)
{
LastNode.Father.LeftSon = null;
}
else
{
LastNode.Father.RightSon = null;
}
}
OrderUptoDown(Root);
PatientsNumber--;
return(FirstNode);
}
/// <summary>
/// Swaps the current node with its father
/// </summary>
/// <param name="node"></param> The node being exchanged
private void ChangeNodes(PQNode <T> node)
{
var Priority1 = node.Priority;
var Key1 = node.Key;
var Date1 = node.DatePriority;
var Patient1 = node.Patient;
node.Priority = node.Father.Priority;
node.Key = node.Father.Key;
node.DatePriority = node.Father.DatePriority;
node.Patient = node.Father.Patient;
node.Father.Priority = Priority1;
node.Father.Key = Key1;
node.Father.DatePriority = Date1;
node.Father.Patient = Patient1;
}
/// <summary>
/// Compare priorities and change if necessary, sort from current node to root
/// </summary>
/// <param name="current"></param> Represents the node being evaluated
private void OrderDowntoUp(PQNode <T> current)
{
if (current.Father != null)
{
if (current.Priority < current.Father.Priority)
{
ChangeNodes(current);
}
else if (current.Priority == current.Father.Priority)
{
if (current.DatePriority < current.Father.DatePriority)
{
ChangeNodes(current);
}
}
OrderDowntoUp(current.Father);
}
}
/// <summary>
/// It searches the last node added to the Priority Queue.
/// </summary>
/// <param name="current"></param> The current node being evaluated.
/// <param name="number"></param> Total number of elements
/// <returns></returns>
private PQNode <T> SearchLastNode(PQNode <T> current, int number)
{
try
{
int previousn = PatientsNumber;
if (previousn == number)
{
return(current);
}
else
{
while (previousn / 2 != number)
{
previousn = previousn / 2;
}
if (previousn % 2 == 0)
{
if (current.LeftSon != null)
{
return(SearchLastNode(current.LeftSon, previousn));
}
else
{
return(current);
}
}
else
{
if (current.RightSon != null)
{
return(SearchLastNode(current.RightSon, previousn));
}
else
{
return(current);
}
}
}
}
catch
{
return(current);
}
}
/// <summary>
/// Compare priorities and change if necessary, sort from root to the leaves
/// </summary>
/// <param name="current"></param> Represents the node being evaluated
private void OrderUptoDown(PQNode <T> current)
{
if (current.RightSon != null && current.LeftSon != null)
{
if (current.LeftSon.Priority > current.RightSon.Priority)
{
if (current.Priority > current.RightSon.Priority)
{
ChangeNodes(current.RightSon);
OrderUptoDown(current.RightSon);
}
else if (current.Priority == current.RightSon.Priority)
{
if (current.DatePriority > current.RightSon.DatePriority)
{
ChangeNodes(current.RightSon);
OrderUptoDown(current.RightSon);
}
}
}
else if (current.LeftSon.Priority < current.RightSon.Priority)
{
if (current.Priority > current.LeftSon.Priority)
{
ChangeNodes(current.LeftSon);
OrderUptoDown(current.LeftSon);
}
else if (current.Priority == current.LeftSon.Priority)
{
if (current.DatePriority > current.LeftSon.DatePriority)
{
ChangeNodes(current.LeftSon);
OrderUptoDown(current.LeftSon);
}
}
}
else
{
if (current.LeftSon.DatePriority > current.RightSon.DatePriority)
{
if (current.Priority > current.RightSon.Priority)
{
ChangeNodes(current.RightSon);
OrderUptoDown(current.RightSon);
}
else if (current.Priority == current.RightSon.Priority)
{
if (current.DatePriority > current.RightSon.DatePriority)
{
ChangeNodes(current.RightSon);
OrderUptoDown(current.RightSon);
}
}
}
else
{
if (current.Priority > current.LeftSon.Priority)
{
ChangeNodes(current.LeftSon);
OrderUptoDown(current.LeftSon);
}
else if (current.Priority == current.LeftSon.Priority)
{
if (current.DatePriority > current.LeftSon.DatePriority)
{
ChangeNodes(current.LeftSon);
OrderUptoDown(current.LeftSon);
}
}
}
}
}
else if (current.RightSon != null)
{
if (current.Priority > current.RightSon.Priority)
{
ChangeNodes(current.RightSon);
OrderUptoDown(current.RightSon);
}
else if (current.Priority == current.RightSon.Priority)
{
if (current.DatePriority > current.RightSon.DatePriority)
{
ChangeNodes(current.RightSon);
OrderUptoDown(current.RightSon);
}
}
}
else if (current.LeftSon != null)
{
if (current.Priority > current.LeftSon.Priority)
{
ChangeNodes(current.LeftSon);
OrderUptoDown(current.LeftSon);
}
else if (current.Priority == current.LeftSon.Priority)
{
if (current.DatePriority > current.LeftSon.DatePriority)
{
ChangeNodes(current.LeftSon);
OrderUptoDown(current.LeftSon);
}
}
}
}