public PQNode findPertinentRoot(PQNode node) {
if (node.isLeaf()) {
if (node.getGraphNode() == myNodeToMerge) {
node.setState(PQNode.State.FULL);
node.setNumFullLeaves(1);
} else {
node.setState(PQNode.State.EMPTY);
node.setNumFullLeaves(0);
}
return node;
} else {
PQNode pertinentRootCandidate = null;
int numFullChildren = 0;
int numEmptyChildren = 0;
int numPartialChildren = 0;
int numFullLeaves = 0;
for (PQNode child : ListSequence.fromList(node.getChildren())) {
PQNode childPertinentRoot = findPertinentRoot(child);
numFullLeaves += child.getNumFullLeaves();
if (child.getState() == PQNode.State.EMPTY) {
numEmptyChildren++;
} else {
pertinentRootCandidate = childPertinentRoot;
if (child.getState() == PQNode.State.FULL) {
numFullChildren++;
}
if (child.getState() == PQNode.State.PARTIAL) {
numPartialChildren++;
}
}
}
node.setNumFullLeaves(numFullLeaves);
if (numPartialChildren > 0) {
node.setState(PQNode.State.PARTIAL);
} else {
int numChildren = ListSequence.fromList(node.getChildren()).count();
if (numFullChildren == numChildren) {
node.setState(PQNode.State.FULL);
} else if (numEmptyChildren == numChildren) {
node.setState(PQNode.State.EMPTY);
} else {
node.setState(PQNode.State.PARTIAL);
}
}
if (numPartialChildren + numFullChildren == 1) {
return pertinentRootCandidate;
} else {
return node;
}
}
}
public PQNode modifyTree(Node nodeToMerge) {
myNodeToMerge = nodeToMerge;
String oldTreeRepresentation = this.toString();
int oldNumFullLeaves = findPertinentRoot(myRoot).getNumFullLeaves();
makeReducible();
PQNode pertinentRoot = findPertinentRoot(myRoot);
int numFullLeaves = pertinentRoot.getNumFullLeaves();
if (SHOW_LOG > 0) {
if (oldNumFullLeaves > numFullLeaves) {
System.out.println("Graph has been made reductible!");
System.out.println("before:");
System.out.println(oldTreeRepresentation);
System.out.println("after:");
System.out.println(this);
}
}
if (numFullLeaves == 1) {
pertinentRoot = pertinentRoot.getParent();
List<PQNode> children = pertinentRoot.getChildren();
ListIterator<PQNode> childItr = children.listIterator();
PNode newNode = null;
while (childItr.hasNext()) {
PQNode child = childItr.next();
if (child.getState() == PQNode.State.FULL) {
newNode = new PNode(nodeToMerge, ((PNode) child).getEdge());
newNode.setParent(pertinentRoot);
childItr.set(newNode);
}
}
return newNode;
} else {
List<PQNode> modifiedChildren = ListSequence.fromList(new ArrayList<PQNode>());
if (pertinentRoot instanceof QNode) {
PQNode prePertinentRoot = pertinentRoot.getParent();
for (PQNode child : ListSequence.fromList(prePertinentRoot.getChildren())) {
if (child == pertinentRoot) {
ListSequence.fromList(modifiedChildren).addElement(arrange(child, true));
} else {
ListSequence.fromList(modifiedChildren).addElement(arrange(child, false));
}
}
for (PQNode child : ListSequence.fromList(modifiedChildren)) {
child.setParent(prePertinentRoot);
}
return prePertinentRoot.processAsPertinentRoot(modifiedChildren, nodeToMerge);
} else {
for (PQNode child : ListSequence.fromList(pertinentRoot.getChildren())) {
ListSequence.fromList(modifiedChildren).addElement(arrange(child, false));
}
for (PQNode child : ListSequence.fromList(modifiedChildren)) {
child.setParent(pertinentRoot);
}
return pertinentRoot.processAsPertinentRoot(modifiedChildren, nodeToMerge);
}
}
}