void link(HeapNode y, HeapNode x) {
// moves y to a child position of x
rootList.remove(y);
x.addChild(y);
y.setParent(x);
y.setMark(false);
}
/**
* removes child node from tree and starts a new one with it.
*
* @param x
* @param y
*/
protected void cut(HeapNode x, HeapNode y) {
// remove x from child list of y and decrement y.degree
y.removeChild(x);
// add x to root list
rootList.insert(x);
x.setParent(null);
x.setMark(false);
}
/**
* c*O(1)
*
* @param y
*/
protected void cascadingCut(HeapNode y) {
HeapNode z = y.getParent();
if (z != null) {
if (!y.isMark()) {
y.setMark(true);
} else {
cut(y, z);
cascadingCut(z);
}
}
}
/**
* insert node into heap. runtime is O(1). makes no attempt to consolidate tree.
*
* @param node
*/
public void insert(HeapNode node) {
if (node.getKey() == DoubleLinkedCircularList.noValue) {
throw new IllegalArgumentException("node.key must be set before insert into heap");
}
node.setNumberOfChildren(0);
node.setParent(null);
node.removeChildren();
node.setLeft(node);
node.setRight(node);
node.setMark(false);
// concatenate root list containing node with this.rootList
rootList.insert(node);
if ((minimumNode == null) || (node.getKey() < minimumNode.getKey())) {
minimumNode = node;
}
n++;
}