/// <summary>
/// Returns a dictionary of chosen encoding bytes for each distinct T.
/// </summary>
public Dictionary <T, byte[]> Compress(T[] input)
{
var frequencies = computeFrequency(input);
var minHeap = new BHeap <FrequencyWrap>();
foreach (var frequency in frequencies)
{
minHeap.Insert(new FrequencyWrap(
frequency.Key, frequency.Value));
}
while (minHeap.Count > 1)
{
var a = minHeap.Extract();
var b = minHeap.Extract();
var newNode = new FrequencyWrap(
default(T), a.Frequency + b.Frequency);
newNode.Left = a;
newNode.Right = b;
minHeap.Insert(newNode);
}
var root = minHeap.Extract();
var result = new Dictionary <T, byte[]>();
dfs(root, new List <byte>(), result);
return(result);
}
public void Max_BHeap_Test()
{
var rnd = new Random();
var initial = new List <int>(Enumerable.Range(0, 51)
.OrderBy(x => rnd.Next()));
var maxHeap = new BHeap <int>(true, initial);
for (int i = 51; i <= 99; i++)
{
maxHeap.Insert(i);
}
for (int i = 0; i <= 99; i++)
{
var max = maxHeap.Extract();
Assert.AreEqual(max, 99 - i);
}
//IEnumerable tests.
Assert.AreEqual(maxHeap.Count, maxHeap.Count());
var testSeries = Enumerable.Range(1, 49)
.OrderBy(x => rnd.Next()).ToList();
foreach (var item in testSeries)
{
maxHeap.Insert(item);
}
for (int i = 1; i <= 49; i++)
{
var max = maxHeap.Extract();
Assert.AreEqual(max, 49 - i + 1);
}
//IEnumerable tests.
Assert.AreEqual(maxHeap.Count, maxHeap.Count());
}
public void Min_BHeap_Test()
{
var rnd = new Random();
var initial = Enumerable.Range(0, 51).OrderBy(x => rnd.Next()).ToList();
var minHeap = new BHeap <int>(false, initial);
for (int i = 51; i <= 99; i++)
{
minHeap.Insert(i);
}
for (int i = 0; i <= 99; i++)
{
var min = minHeap.Extract();
Assert.AreEqual(min, i);
}
//IEnumerable tests.
Assert.AreEqual(minHeap.Count, minHeap.Count());
var testSeries = Enumerable.Range(1, 49).OrderBy(x => rnd.Next()).ToList();
foreach (var item in testSeries)
{
minHeap.Insert(item);
}
for (int i = 1; i <= 49; i++)
{
var min = minHeap.Extract();
Assert.AreEqual(min, i);
}
//IEnumerable tests.
Assert.AreEqual(minHeap.Count, minHeap.Count());
}
/// <summary>
/// Do DFS to pick smallest weight neighbour edges
/// of current spanning tree one by one.
/// </summary>
/// <param name="spanTreeNeighbours"> Use Fibonacci Min Heap to pick smallest edge neighbour </param>
/// <param name="spanTreeEdges">result MST edges</param>
private void dfs(WeightedGraph <T, W> graph, WeightedGraphVertex <T, W> currentVertex,
BHeap <MSTEdge <T, W> > spanTreeNeighbours, HashSet <T> spanTreeVertices,
List <MSTEdge <T, W> > spanTreeEdges)
{
while (true)
{
//add all edges to Fibonacci Heap
//So that we can pick the min edge in next step
foreach (var edge in currentVertex.Edges)
{
spanTreeNeighbours.Insert(new MSTEdge <T, W>(currentVertex.Value, edge.Key.Value, edge.Value));
}
//pick min edge
var minNeighbourEdge = spanTreeNeighbours.Extract();
//skip edges already in MST
while (spanTreeVertices.Contains(minNeighbourEdge.Source) && spanTreeVertices.Contains(minNeighbourEdge.Destination))
{
minNeighbourEdge = spanTreeNeighbours.Extract();
//if no more neighbours to explore
//time to end exploring
if (spanTreeNeighbours.Count == 0)
{
return;
}
}
//keep track of visited vertices
//do not duplicate vertex
if (!spanTreeVertices.Contains(minNeighbourEdge.Source))
{
spanTreeVertices.Add(minNeighbourEdge.Source);
}
//Destination vertex will never be a duplicate
//since this is an unexplored Vertex
spanTreeVertices.Add(minNeighbourEdge.Destination);
//add edge to result
spanTreeEdges.Add(minNeighbourEdge);
//now explore the destination vertex
var graph1 = graph;
currentVertex = graph1.Vertices[minNeighbourEdge.Destination];
}
}
private void enqueueIntersectionEvent(Event currentEvent, Point intersection)
{
if (intersection == null)
{
return;
}
var intersectionEvent = new Event(intersection, pointComparer, EventType.Intersection, null, this);
if (intersectionEvent.X > SweepLine.Left.X ||
(intersectionEvent.X == SweepLine.Left.X &&
intersectionEvent.Y > currentEvent.Y))
{
if (!eventQueueLookUp.Contains(intersectionEvent))
{
eventQueue.Insert(intersectionEvent);
eventQueueLookUp.Add(intersectionEvent);
}
}
}