public static Node Create(int key)
{
Node node = new Node();
node.key = key;
return node;
}
// Linking nodes
public void Link(Node child, Node parent)
{
child.parent = parent;
child.sibling = parent.child;
parent.child = child;
parent.degree = parent.degree + 1;
}
// Insert node
public Node Insert(Node h, Node insertNode)
{
Node node = Init();
node = insertNode;
h = Union(h, node);
return h;
}
// Union nodes
public Node Union(Node h1, Node h2)
{
Node node = Init();
node = Merge(h1, h2);
if (node == null)
{
return node;
}
Node h = node;
Node prevH = null;
Node nextH = h.sibling;
while (nextH != null)
{
if ((h.degree != nextH.degree) || ((nextH.sibling != null) && (nextH.sibling).degree == h.degree))
{
prevH = h;
h = nextH;
}
else
{
if (h.key <= nextH.key)
{
h.sibling = nextH.sibling;
Link(nextH, h);
}
else
{
if (prevH == null)
{
node = nextH;
}
else
{
prevH.sibling = nextH;
}
Link(h, nextH);
h = nextH;
}
}
nextH = h.sibling;
}
return node;
}
public BinomialHeap()
{
heap = Init();
heapR = Init();
}
// Delete Nodes
public void Delete(Node h, int key)
{
if (h == null)
{
Console.WriteLine("Heap is empty");
return;
}
DecreaseKey(h, key, int.MinValue);
ExtractMinimum(h);
}
// Decrease key of a node
public void DecreaseKey(Node h, int curKey, int newKey)
{
if (newKey > curKey)
{
Console.WriteLine("The new key cannot exceed the current");
return;
}
Node foundNode = Search(h, curKey);
if (foundNode == null)
{
Console.WriteLine("Node not found");
return;
}
foundNode.key = newKey;
Node a = foundNode;
Node b = foundNode.parent;
while (b != null && a.key < b.key)
{
int temp = a.key;
a.key = b.key;
b.key = temp;
a = b;
b = b.parent;
}
}
// Search
private Node Search(Node h, int key)
{
Node result = Init();
if (h.key == key)
{
result = h;
return result;
}
if (h.child != null && result == null)
{
result = Search(h.child, key);
}
if (h.sibling != null && result == null)
{
result = Search(h.sibling, key);
}
return result;
}
// Reverse list
private void Reverse(Node h)
{
if (h.sibling != null)
{
Reverse(h.sibling);
(h.sibling).sibling = h;
}
else
{
heapR = h;
}
}
// Extract minimum
public Node ExtractMinimum(Node h)
{
if (h == null)
{
Console.WriteLine("Heap is empty");
return h;
}
heapR = Init();
Node a = Init();
Node node = h;
Node temp = node;
int min = node.key;
while (temp.sibling != null)
{
if ((temp.sibling).key < min)
{
min = (temp.sibling).key;
a = temp;
node = temp.sibling;
}
temp = temp.sibling;
}
if (a == null && node.sibling == null)
{
h = null;
}
else if (a == null)
{
h = node.sibling;
}
else if (a.sibling == null)
{
a = null;
}
else
{
a.sibling = node.sibling;
}
if (node.child != null)
{
Reverse(node.child);
(node.child).sibling = null;
}
heap = Union(h, heapR);
return node;
}
// Merge nodes
public Node Merge(Node h1, Node h2)
{
Node node = Init();
Node tmp = Init();
if (h1 != null)
{
if (h2 != null)
{
if (h1.degree <= h2.degree)
{
node = h1;
}
else if (h1.degree > h2.degree)
{
node = h2;
}
}
else
{
node = h1;
}
}
else
{
node = h2;
}
while (h1 != null && h2 != null)
{
if (h1.degree < h2.degree)
{
h1 = h1.sibling;
}
else if (h1.degree == h2.degree)
{
tmp = h1.sibling;
h1.sibling = h2;
h1 = tmp;
}
else
{
tmp = h2.sibling;
h2.sibling = h1;
h2 = tmp;
}
}
return node;
}
