Bnode merge(Bnode parent, int position)
{
Bnode left = parent.children[position];
Bnode right = parent.children[position + 1];
int newPosition = left.insert(parent.keys[position]);
moveParent(left, newPosition + 1, right.children[0]);
for (int i = 0; i < right.n; i++)
{
newPosition = left.insert(right.keys[i]);
moveParent(left, newPosition + 1, right.children[i + 1]);
}
parent.delete(position);
return(left);
}
void rightRotate(Bnode parent, int position)
{
Bnode left = parent.children[position];
Bnode right = parent.children[position + 1];
int newPosition = right.insert(parent.keys[position]);
right.children[1] = right.children[0];
moveParent(right, newPosition, left.children[left.n]);
parent.keys[position] = left.keys[left.n - 1];
left.n--;
}
void leftRotate(Bnode parent, int position)
{
Bnode left = parent.children[position];
Bnode right = parent.children[position + 1];
int newPosition = left.insert(parent.keys[position]);
moveParent(left, newPosition + 1, right.children[0]);
parent.keys[position] = right.keys[0];
right.children[0] = right.children[1];
right.delete(0);
}
public void insert(ref Bnode root, int key)
{
int currentDepth = 0;
if (root == null)
{
root = new Bnode(m);//,0);
root.insert(key);
}
else
{
Bnode current = root;
while (true)
{
if (current.children[0] == null) //insert must be in leaf
{
int position = current.insert(key);
while (current.n > current.size) //overflow
//split the node
{
Object[] result = split(ref root, current, currentDepth);
//try to insert middle key to parent
Bnode newNode = (Bnode)result[0];
key = (int)result[1]; //separator
current = current.parent;
position = current.insert(key);
current.children[position + 1] = newNode;
}
break;
}
current = current.children[current.findPosition(key)];
currentDepth++;
}
}
}
// other
Object[] split(ref Bnode root, Bnode node, int currentDepth)
{
int mid = node.n / 2;
if (node.parent == null)
{
root = new Bnode(m);//, currentDepth);
root.children[0] = node;
node.parent = root;
}
Bnode newNode = new Bnode(m);//, currentDepth);
newNode.parent = node.parent;
int nk = 0;
for (int k = mid + 1; k < node.n; k++, nk++)
{
newNode.insert(node.keys[k]);
moveParent(newNode, nk, node.children[k]);
}
moveParent(newNode, nk, node.children[node.n]);
node.n = mid;
return(new Object[] { newNode, node.keys[mid] });
}