/// <summary>
/// Put an element into this priority queue. The element is inserted into the index found by BinarySearchUtil.SearchProximity. (Ave. O(log(n))).
/// </summary>
/// <param name="priority"></param>
/// <param name="item"></param>
public void Put(P priority, T item)
{
PriorityQueueItem <P, T> newItem = new PriorityQueueItem <P, T>(priority, item);
int idx = BinarySearchUtil.SearchProximity(newItem, ItemQueue);
if (ItemQueue.Count == 0)
{
ItemQueue.Add(newItem);
}
else
{
if (idx == 0 && newItem.CompareTo(ItemQueue[0]) < 0)
{
ItemQueue.Insert(0, newItem);
}
else if (idx + 1 < ItemQueue.Count)
{
ItemQueue.Insert(idx + 1, newItem);
}
else
{
ItemQueue.Add(newItem);
}
}
}
/// <summary>
/// Override fuction from <c>IComparable</c>.
/// </summary>
/// <param name="obj"></param>
/// <returns></returns>
public int CompareTo(object obj)
{
if (obj == null)
{
return(1);
}
PriorityQueueItem <P, T> otherObj = obj as PriorityQueueItem <P, T>;
return(Priority.CompareTo(otherObj.Priority));
}
/// <summary>
/// Pop the first element in this priority queue.
/// </summary>
/// <returns></returns>
public PriorityQueueItem <P, T> Pop()
{
if (ItemQueue.Count > 0)
{
PriorityQueueItem <P, T> popItem = ItemQueue[0];
ItemQueue.RemoveAt(0);
return(popItem);
}
else
{
return(null);
}
}
/// <summary>
/// Remove the first element that has its item reference equals to the param. (Worst O(n)).
/// </summary>
/// <param name="item"></param>
public void Remove(T item)
{
int idx = -1;
for (int i = 0; i < ItemQueue.Count; i++)
{
PriorityQueueItem <P, T> queueItem = ItemQueue[i];
if (Object.ReferenceEquals(queueItem.Item, item))
{
idx = i;
break;
}
}
if (idx != -1)
{
ItemQueue.RemoveAt(idx);
}
}