private BTNode getExtendedNode(BTNode fullNode) {
BTNode newNode = new BTNode();
newNode.number = t - 1;
newNode.isLeaf = fullNode.isLeaf;
for (int i = 0; i < t; i++) {
if (i != t - 1) {
newNode.AddKey(i, fullNode.getKey(t + i));
}
newNode.AddChildren(i, fullNode.getChildren(t + i));
}
return newNode;
}
public void insertElem(E elem) {
if (root == null) {
// The first node
constructRoot(elem);
root.isLeaf = true;
root.AddChildren(0, NullBTNode);
root.AddChildren(1, NullBTNode);
return;
}
BTNode curNode = root;
if (root.isFull()) {
// Extend the root
constructRoot(curNode.getKey(t - 1));
// Get new node
BTNode newNode = getExtendedNode(curNode);
// Process old full node
processFullNode(curNode);
// Process root
root.AddChildren(0, curNode);
root.AddChildren(1, newNode);
return;
}
int i = 0;
BTNode childNode = null;
// Find the node to insert
while (true) {
while ((i < curNode.getSize()) && (elem.compareTo(curNode.getKey(i)) > 0)) {
i++;
}
childNode = curNode.getChildren(i);
if (childNode.isFull()) {
// Split the node
// Add the element to parent
curNode.number++;
curNode.AddKey(i, childNode.getKey(t - 1));
// New node for extension
BTNode newNode = getExtendedNode(childNode);
// Process old full node
processFullNode(childNode);
// Add the new node for parent reference
curNode.AddChildren(i + 1, newNode);
// Down to low layer
if (elem.compareTo(curNode.getKey(i)) < 0) {
curNode = childNode;
} else {
curNode = newNode;
}
i = 0;
continue;
}
// Down to child node
if (!childNode.isNull()) {
curNode = childNode;
i = 0;
continue;
}
// Insert the element in current node
addElemToNode(curNode, elem, i);
return;
}
}
private void addElemToNode(BTNode node, E element, int i) {
node.AddKey(i, element);
node.number++;
node.AddChildren(i, NullBTNode);
}
// Generate the root node
private void constructRoot(E elem) {
root = new BTNode();
root.number = 1;
root.AddKey(0, elem);
root.isLeaf = false;
}