public static node minimum(node1 head)
{
node m = head.root;
for (int i = 0; i < head.height; ++i)
{
if (m.child1.key == m.key)
{
m = m.child1;
}
else if (m.child2.key == m.key)
{
m = m.child2;
}
else if (m.child3.key == m.key)
{
m = m.child3;
}
else if (m.child4.key == m.key)
{
m = m.child4;
}
}
return(m);
}
public static void insert(ref node1 h1, node x)
{
if (h1.height == -1)
{
h1.root = x;
h1.height = 0;
}
else
{
node1 h2 = new node1(0, x);
h1 = union234(h1, h2);
}
}
static void Main(string[] args)
{
node1 head = node1.makeHeap();
node node_1 = new node(2);
insert(ref head, node_1);
for (int i = 0; i < 10; i++)
{
node node_2 = new node(i + 3);
insert(ref head, node_2);
}
//remove(head,node_2);
display(head.root);
Console.Read();
}
public static void decreaseKey(node1 head, node x, int k)
{
if (k > x.key)
{
Console.Write("error");
}
else
{
x.key = k;
node p = x;
while (p.parent != null && p.parent.key > k)
{
p.parent.key = k;
p = p.parent;
}
}
}
public static node1 union234(node1 heap1, node1 heap2)
{
if (heap1.height == heap2.height)
{
node root = new node(Math.Min(heap1.root.key, heap2.root.key), 2, null, heap1.root, heap2.root);
node1 head = new node1(heap1.height + 1, root);
return(head);
}
if (heap2.height > heap1.height)
{
swap(ref heap1, ref heap2);
}
node p = heap1.root;
if (p.degree == 4)
{
node l = new node(Math.Min(p.child1.key, p.child2.key), 2, null, p.child1, p.child2);
node r = new node(Math.Min(p.child3.key, p.child4.key), 2, null, p.child3, p.child4);
node pr = new node(Math.Min(l.key, r.key), 2, null, l, r);
l.parent = pr;
r.parent = pr;
heap1.root = pr;
heap1.height++;
}
p = heap1.root;
for (int i = 0; i < heap1.height - heap2.height - 1; ++i)
{
if (p.degree < 4)
{
if (p.child3 != null && p.child3.degree < 4)
{
p = p.child3;
}
else if (p.child2 != null && p.child2.degree < 4)
{
p = p.child2;
}
else
{
p = p.child1;
}
}
else
{
if (p.parent.child3 == null)
{
p.parent.child3 = new node(Math.Min(p.child3.key, p.child4.key), 2, p.child3, p.child4);
--i;
}
else
{
p.parent.child4 = new node(Math.Min(p.child3.key, p.child4.key), 2, p.child3, p.child4);
--i;
}
p.parent.degree++;
p.degree -= 2;
}
}
if (p.degree < 4)
{
if (p.child3 == null)
{
p.child3 = heap2.root;
p.child3.parent = p;
p.child3.degree = heap2.root.degree;
p.child3.child1 = heap2.root.child1;
p.child3.child2 = heap2.root.child2;
p.child3.child3 = heap2.root.child3;
p.child3.child4 = heap2.root.child4;
p.degree++;
}
else
{
p.child4 = heap2.root;
p.child4.parent = p;
p.child4.degree = heap2.root.degree;
p.child4.child1 = heap2.root.child1;
p.child4.child2 = heap2.root.child2;
p.child4.child3 = heap2.root.child3;
p.child4.child4 = heap2.root.child4;
p.degree++;
}
}
else
{
if (p.parent.child3 == null)
{
p.parent.child3 = new node(Math.Min(p.child3.key, p.child4.key), 2, p.child3, p.child4);
}
else
{
p.parent.child4 = new node(Math.Min(p.child3.key, p.child4.key), 2, p.child3, p.child4);
}
p.parent.degree++;
p.degree -= 2;
p.parent.child3.child3 = heap2.root;
p.parent.child3.child3.degree++;
}
p = heap2.root;
while (p.parent != null)
{
if (p.parent.key > p.key)
{
p.parent.key = p.key;
}
else
{
break;
}
}
return(heap1);
}
public static void remove(node1 head, ref node x) //deletes a given leaf x
{
decreaseKey(head, x, -1);
extractMin(head);
}
public static node1 makeHeap()
{
node1 head = new node1();
return(head);
}
public static node extractMin(node1 head) //extracts a leaf with the smallest key; returns the node with the smallest key
{
node mini = minimum(head);
if (mini == head.root || mini.parent == null)
{
head.root = null;
head.height--;
return(null);
}
if (mini.parent == head.root && head.root.degree == 2)
{
head.root = new node(Math.Max(head.root.child1.key, head.root.child2.key), 0);
head.height--;
return(head.root);
} //simplest cases
node p = mini;
node q = p;
if (mini.parent.degree > 2) //not so complicated case: we can delete it and then aligne
{
if (mini == mini.parent.child1)
{
swap(ref mini.parent.child1, ref mini.parent.child2);
}
if (mini == mini.parent.child2)
{
swap(ref mini.parent.child2, ref mini.parent.child3);
}
if (mini == mini.parent.child3 && mini.parent.child4 != null)
{
swap(ref mini.parent.child3, ref mini.parent.child4);
}
mini.parent.degree--;
if (mini.parent.child4 != null)
{
mini.parent.child4 = null;
}
else
{
mini.parent.child3 = null;
}
}
else //its parent has only 2 childs
{
p = mini.parent;
mini = null;
if (p.child1 == null)
{
swap(ref p.child1, ref p.child2);
}
p.key = p.child1.key;
p.degree--;
while (true) //we can get til the root
{
if (p.parent == null) //it got to the root
{
q = head.root = p.child1;
head.height--;
break;
}
else
{
if (p.parent.degree > 2) //we can fix it with 1 step
{
if (p.parent.child1.degree != 1) // we can get him a sibling form here
{
if (p.parent.child1.degree == 2) // we move the single leaf
{
p.parent.child1.child3 = p.child1;
p.parent.child1.degree++;
p.parent.degree--;
p.parent.child1.key = Math.Min(p.parent.child1.key, p.parent.child1.child3.key);
if (p == p.parent.child1) // we gotta align
{
swap(ref p.parent.child1, ref p.parent.child2);
}
if (p == p.parent.child2)
{
swap(ref p.parent.child2, ref p.parent.child3);
}
if (p == p.parent.child3 && p.parent.child4 != null)
{
swap(ref p.parent.child3, ref p.parent.child4);
}
if (p.parent.child4 != null)
{
p.parent.child4 = null;
}
else
{
p.parent.child3 = null;
}
p.parent.key = Math.Min(p.parent.child1.key, p.parent.child2.key); //refreshing the keys
if (p.parent.child3 != null)
{
p.parent.key = Math.Min(p.parent.child3.key, p.parent.key);
}
}
else // we get a sibling for him from his uncle
{
if (p.parent.child1.child4 != null)
{
p.child2 = p.parent.child1.child4;
p.parent.child1.child4 = null;
p.parent.child1.degree--;
p.degree++;
}
else
{
p.child2 = p.parent.child1.child3;
p.parent.child1.child3 = null;
p.parent.child1.degree--;
p.degree++;
}
p.parent.child1.key = Math.Min(p.parent.child1.child1.key, p.parent.child1.child2.key); //key refreshing
if (p.parent.child1.child3 != null)
{
p.parent.child1.key = Math.Min(p.parent.child1.key, p.parent.child1.child3.key);
}
if (p.parent.child1.child4 != null)
{
p.parent.child1.key = Math.Min(p.parent.child1.key, p.parent.child1.child4.key);
}
p.key = Math.Min(p.child1.key, p.child2.key);
p.parent.key = Math.Min(p.parent.child1.key, p.parent.child2.key);
if (p.parent.child3 != null)
{
p.parent.key = Math.Min(p.parent.child3.key, p.parent.key);
}
if (p.parent.child4 != null)
{
p.parent.key = Math.Min(p.parent.child4.key, p.parent.key);
}
}
}
else if (p.parent.child2.degree != 1) // we can get him a sibling form here
{
if (p.parent.child2.degree == 2) // we move teh single leaf
{
p.parent.child2.child3 = p.child1;
p.parent.child2.degree++;
p.parent.degree--;
p.parent.child2.key = Math.Min(p.parent.child2.key, p.parent.child2.child3.key);
if (p == p.parent.child1) //aligning
{
swap(ref p.parent.child2, ref p.parent.child2);
}
if (p == p.parent.child2)
{
swap(ref p.parent.child2, ref p.parent.child3);
}
if (p == p.parent.child3 && p.parent.child4 != null)
{
swap(ref p.parent.child3, ref p.parent.child4);
}
if (p.parent.child4 != null)
{
p.parent.child4 = null;
}
else
{
p.parent.child3 = null;
}
p.parent.key = Math.Min(p.parent.child1.key, p.parent.child2.key); //refreshing the keys
if (p.parent.child3 != null)
{
p.parent.key = Math.Min(p.parent.child3.key, p.parent.key);
}
}
else //we get him a siblin gfrom his uncle
{
if (p.parent.child2.child4 != null)
{
p.child2 = p.parent.child2.child4;
p.parent.child2.child4 = null;
p.parent.child2.degree--;
p.degree++;
}
else
{
p.child2 = p.parent.child2.child3;
p.parent.child2.child3 = null;
p.parent.child2.degree--;
p.degree++;
}
p.parent.child2.key = Math.Min(p.parent.child2.child1.key, p.parent.child2.child2.key);
if (p.parent.child1.child3 != null)
{
p.parent.child2.key = Math.Min(p.parent.child2.key, p.parent.child2.child3.key);
}
if (p.parent.child2.child4 != null)
{
p.parent.child2.key = Math.Min(p.parent.child2.key, p.parent.child2.child4.key);
}
p.key = Math.Min(p.child1.key, p.child2.key);
p.parent.key = Math.Min(p.parent.child1.key, p.parent.child2.key);
if (p.parent.child3 != null)
{
p.parent.key = Math.Min(p.parent.child3.key, p.parent.key);
}
if (p.parent.child4 != null)
{
p.parent.key = Math.Min(p.parent.child4.key, p.parent.key); //keys resfreshed
}
}
}
q = p;
break;
}
else
{
if (p.parent.child1.degree != 1)
{
if (p.parent.child1.degree > 2) //getting him a sibling from his uncle
{
if (p.parent.child1.child4 != null)
{
p.child2 = p.parent.child1.child4;
p.parent.child1.child4 = null;
}
else
{
p.child2 = p.parent.child1.child3;
p.parent.child1.child3 = null;
}
p.parent.child1.degree--;
p.parent.key = Math.Min(p.parent.child1.key, p.parent.child2.key); //surely refreshing the keys
if (p.parent.child3 != null)
{
p.parent.key = Math.Min(p.parent.key, p.parent.child3.key);
}
p.degree++;
q = p;
break;
}
else // the megaworst case
{
p.parent.child1.child3 = p.child1;
p.parent.child1.degree++;
p.parent.degree--;
p.child1 = null;
p = p.parent;
p.child1.key = Math.Min(p.child1.key, p.child1.child3.key);
p.key = p.child1.key;
p.child2 = null;
}
}
else if (p.parent.child2.degree != 1)
{
if (p.parent.child2.degree > 2) //getting him a sibling from his uncle
{
if (p.parent.child2.child4 != null)
{
p.child2 = p.parent.child2.child4;
p.parent.child2.child4 = null;
}
else
{
p.child2 = p.parent.child2.child3;
p.parent.child2.child3 = null;
}
p.parent.child2.degree--;
p.parent.key = Math.Min(p.parent.child1.key, p.parent.child2.key); //surely refreshing the keys
if (p.parent.child3 != null)
{
p.parent.key = Math.Min(p.parent.key, p.parent.child3.key);
}
p.degree++;
}
else // the meagworst case
{
p.parent.child2.child3 = p.child1;
p.parent.child2.degree++;
swap(ref p.parent.child2, ref p);
p.parent.degree--;
p.child1 = null;
p = p.parent;
p.child2 = null;
}
}
}
}
}
}
while (q.parent == q.parent) // refreshing the minimum of the whole heap
{
q = q.parent;
q.key = Math.Min(q.child1.key, q.child2.key);
if (q.child3 == q.child3)
{
q.key = Math.Min(q.key, q.child3.key);
}
if (q.child4 == q.child4)
{
q.key = Math.Min(q.key, q.child4.key);
}
}
return(minimum(head));
}