public void Should_Decrease_Min_Heap()
{
//arrange
var heap = new MyBinaryHeap <int>(MyBinaryHeapType.MinHeap);
heap.Insert(6);
heap.Insert(7);
heap.Insert(12);
heap.Insert(10);
heap.Insert(15);
heap.Insert(17);
//act
heap.Decrease(10, 2);
//assert
heap.Root.Data.ShouldBeEquivalentTo(2);
heap.Root.Left.Data.ShouldBeEquivalentTo(6);
heap.Root.Right.Data.ShouldBeEquivalentTo(12);
heap.Root.Left.Left.Data.ShouldBeEquivalentTo(7);
heap.Root.Left.Right.Data.ShouldBeEquivalentTo(15);
heap.Root.Right.Left.Data.ShouldBeEquivalentTo(17);
heap.Count.ShouldBeEquivalentTo(6);
heap.HeapType.ShouldBeEquivalentTo(MyBinaryHeapType.MinHeap);
}
private Dictionary <T, T?> ComputePaths(T source, MyGraphAdj <T> graph)
{
var vertexes = graph.GetAllVertexes().ToList();
var edges = graph.GetAllEdges().ToList();
Dictionary <T, int> distances = new Dictionary <T, int>();
Dictionary <T, T?> parent = new Dictionary <T, T?>();
Dictionary <T, int> heapMinDistances = new Dictionary <T, int>();
var heap = new MyBinaryHeap <MyBinaryHeapKeyNode <T, int> >(MyBinaryHeapType.MinHeap);
foreach (var vertex in vertexes)
{
heap.Insert(new MyBinaryHeapKeyNode <T, int>(vertex.Key, vertex.Key.CompareTo(source) == 0 ? 0 : Int32.MaxValue));
heapMinDistances.Add(vertex.Key, Int32.MaxValue);
}
parent[source] = null;
distances[source] = 0;
while (heap.Count > 0)
{
var current = heap.ExtractTop();
var nodes = edges.Where(x => x[0].Equals(
vertexes.First(y => y.Key.CompareTo(current.Key) == 0).Value)).ToList();
if (nodes.Count == 0)
{
break;
}
var parentNode = vertexes.First(x => x.Key.CompareTo(current.Key) == 0);
foreach (var node in nodes)
{
var vertex = vertexes.First(x => x.Value == node[1]);
if (!heap.Contains(new MyBinaryHeapKeyNode <T, int>(vertex.Key, vertex.Value)))
{
continue;
}
var currentDistance = edges.First(x =>
x[0] == parentNode.Value && x[1] == vertex.Value)[2];
distances[vertex.Key] = distances[current.Key] + currentDistance;
if (heapMinDistances[vertex.Key] >= distances[vertex.Key])
{
parent[vertex.Key] = current.Key;
heap.Decrease(new MyBinaryHeapKeyNode <T, int>(vertex.Key, Int32.MaxValue),
new MyBinaryHeapKeyNode <T, int>(vertex.Key, currentDistance));
heapMinDistances[vertex.Key] = currentDistance;
}
}
}
return(parent);
}
public void Should_Throw_Decrease_If_Lower_Value_MaxHeap()
{
//arrange
var heap = new MyBinaryHeap <int>(MyBinaryHeapType.MaxHeap);
heap.Insert(17);
heap.Insert(15);
heap.Insert(10);
heap.Insert(6);
heap.Insert(10);
heap.Insert(7);
//act
Action act = () => heap.Decrease(17, 11);
//assert
act.ShouldThrow <ArgumentException>();
heap.Count.ShouldBeEquivalentTo(6);
heap.HeapType.ShouldBeEquivalentTo(MyBinaryHeapType.MaxHeap);
}
public void Should_Throw_Decrease_If_Not_Contains()
{
//arrange
var heap = new MyBinaryHeap <int>(MyBinaryHeapType.MaxHeap);
heap.Insert(17);
heap.Insert(15);
heap.Insert(10);
heap.Insert(6);
heap.Insert(10);
heap.Insert(7);
heap.ExtractTop();
//act
Action act = () => heap.Decrease(17, 11);
//assert
act.ShouldThrow <InvalidOperationException>();
heap.Count.ShouldBeEquivalentTo(5);
heap.HeapType.ShouldBeEquivalentTo(MyBinaryHeapType.MaxHeap);
}
