public TreapDelete(Treap T, int x) {
super(T);
this.T = T;
T.setV(v = new TreapNode(T, K = x));
v.setColor(NodeColor.DELETE);
setHeader("deletion");
}
/**
* Heapify up the treap at the current node to the root.
*
* @param current to heapify.
*/
private void heapify(TreapNode<T> current) {
// Bubble up the heap, if needed
TreapNode<T> parent = (TreapNode<T>) current.parent;
while (parent != null && current.priority > parent.priority) {
Node<T> grandParent = parent.parent;
if (grandParent != null) {
if (grandParent.greater != null && grandParent.greater.equals(parent)) {
// My parent is my grandparents greater branch
grandParent.greater = current;
current.parent = grandParent;
} else if (grandParent.lesser != null && grandParent.lesser.equals(parent)) {
// My parent is my grandparents lesser branch
grandParent.lesser = current;
current.parent = grandParent;
} else {
System.err.println(
"YIKES! Grandparent should have at least one non-NULL child which should be my parent.");
}
current.parent = grandParent;
} else {
root = current;
root.parent = null;
}
if (parent.lesser != null && parent.lesser.equals(current)) {
// LEFT
parent.lesser = null;
if (current.greater == null) {
current.greater = parent;
parent.parent = current;
} else {
Node<T> lost = current.greater;
current.greater = parent;
parent.parent = current;
parent.lesser = lost;
lost.parent = parent;
}
} else if (parent.greater != null && parent.greater.equals(current)) {
// RIGHT
parent.greater = null;
if (current.lesser == null) {
current.lesser = parent;
parent.parent = current;
} else {
Node<T> lost = current.lesser;
current.lesser = parent;
parent.parent = current;
parent.greater = lost;
lost.parent = parent;
}
} else {
// We really shouldn't get here
System.err.println(
"YIKES! Parent should have at least one non-NULL child which should be me.");
}
parent = (TreapNode<T>) current.parent;
}
}
@Override
public void run() {
if (T.getRoot() == null) {
v.goToRoot();
addStep("empty");
mysuspend();
v.goDown();
v.setColor(NodeColor.NOTFOUND);
addStep("notfound");
return;
} else {
TreapNode d = (TreapNode) T.getRoot();
v.goTo(d);
addStep("bstdeletestart");
mysuspend();
while (true) {
if (d.key == K) { // found
v.setColor(NodeColor.FOUND);
break;
} else if (d.key < K) { // right
addStep("bstfindright", K, d.key);
d = d.getRight();
if (d != null) {
v.goTo(d);
} else {
v.goRight();
break;
}
} else { // left
addStep("bstfindleft", K, d.key);
d = d.getLeft();
if (d != null) {
v.goTo(d);
} else {
v.goLeft();
break;
}
}
mysuspend();
}
if (d == null) { // notfound
addStep("notfound");
return;
}
d.setColor(NodeColor.FOUND);
T.setV(null);
addStep("treapbubbledown");
// prebubleme k listu
while (!d.isLeaf()) {
if (d.getLeft() == null) {
T.rotate(d.getRight());
} else if (d.getRight() == null) {
T.rotate(d.getLeft());
} else if (d.getRight().p > d.getLeft().p) {
T.rotate(d.getRight());
} else {
T.rotate(d.getLeft());
}
mysuspend();
}
T.setV(d);
addStep("treapdeletecase1");
mysuspend();
if (d.isRoot()) {
T.setRoot(null);
} else if (d.isLeft()) {
d.getParent().setLeft(null);
} else {
d.getParent().setRight(null);
}
d.goDown();
T.reposition();
addStep("done");
}
}
