public static void validate(@Nullable Node original, Node n) {
if (original != null) {
validate(null, original);
}
if (Null.red) {
trouble(original, n, new RuntimeException("red null!"));
}
if (Null.left != Null || Null.right != Null || Null.value != Null || Null.key != null) {
trouble(original, n, new RuntimeException("corrupted null!"));
}
if (n.red) {
trouble(original, n, new RuntimeException("red root!"));
}
NodeStack s = new NodeStack();
int blackCount = -1;
for (NodeIterator it = new NodeIterator(s, n); it.hasNext(); ) {
int index = it.stack.index;
Node x = it.next();
if (x.key instanceof Node) {
trouble(original, n, new RuntimeException("node key!"));
}
if (x.key == null) {
trouble(original, n, new RuntimeException("null key!"));
}
if (x.value instanceof Node) {
validate(original, (Node) x.value);
}
if (x.red && (x.left.red || x.right.red)) {
trouble(original, n, new RuntimeException("red node has red child(ren)!"));
}
if (x.left == Node.Null && x.right == Node.Null) {
int count = 0;
for (int i = 0; i < index; ++i) {
if (!s.array[i].red) {
++count;
}
}
if (!x.red) {
++count;
}
if (blackCount == -1) {
blackCount = count;
} else if (count != blackCount) {
trouble(
original,
n,
new RuntimeException("inconsistent number of black nodes per paths to leaves!"));
}
}
}
}
public static Node blaze(
BlazeResult result,
Object token,
NodeStack stack,
Node root,
Object key,
Comparator comparator) {
if (key == null) throw new NullPointerException();
if (root == null) {
root = Null;
}
if (Debug) {
token = new Object();
validate(null, root);
}
stack = new NodeStack(stack);
Node newRoot = getNode(token, root);
Node old = root;
Node new_ = newRoot;
while (old != Null) {
int difference = Compare.compare(key, old.key, comparator);
if (difference < 0) {
stack.push(new_);
old = old.left;
new_ = new_.left = getNode(token, old);
} else if (difference > 0) {
stack.push(new_);
old = old.right;
new_ = new_.right = getNode(token, old);
} else {
result.node = new_;
stack.popStack();
if (Debug) {
validate(root, newRoot);
}
return newRoot;
}
}
new_.key = key;
result.node = new_;
// rebalance
new_.red = true;
while (stack.top != null && stack.top.red) {
if (stack.top == stack.peek().left) {
if (stack.peek().right.red) {
stack.top.red = false;
stack.peek().right = getNode(token, stack.peek().right);
stack.peek().right.red = false;
stack.peek().red = true;
new_ = stack.peek();
stack.pop(2);
} else {
if (new_ == stack.top.right) {
new_ = stack.top;
stack.pop();
Node n = leftRotate(token, new_);
if (stack.top.right == new_) {
stack.top.right = n;
} else {
stack.top.left = n;
}
stack.push(n);
}
stack.top.red = false;
stack.peek().red = true;
Node n = rightRotate(token, stack.peek());
if (stack.index <= stack.base + 1) {
newRoot = n;
} else if (stack.peek(1).right == stack.peek()) {
stack.peek(1).right = n;
} else {
stack.peek(1).left = n;
}
// done
}
} else {
// this is just the above code with left and right swapped:
if (stack.peek().left.red) {
stack.top.red = false;
stack.peek().left = getNode(token, stack.peek().left);
stack.peek().left.red = false;
stack.peek().red = true;
new_ = stack.peek();
stack.pop(2);
} else {
if (new_ == stack.top.left) {
new_ = stack.top;
stack.pop();
Node n = rightRotate(token, new_);
if (stack.top.right == new_) {
stack.top.right = n;
} else {
stack.top.left = n;
}
stack.push(n);
}
stack.top.red = false;
stack.peek().red = true;
Node n = leftRotate(token, stack.peek());
if (stack.index <= stack.base + 1) {
newRoot = n;
} else if (stack.peek(1).right == stack.peek()) {
stack.peek(1).right = n;
} else {
stack.peek(1).left = n;
}
// done
}
}
}
newRoot.red = false;
stack.popStack();
if (Debug) {
validate(root, newRoot);
}
return newRoot;
}
public static Node delete(
Object token, NodeStack stack, Node root, Object key, Comparator comparator) {
if (Debug) {
token = new Object();
validate(null, root);
}
if (root == Null) {
return root;
} else if (root.left == Null && root.right == Null) {
if (Compare.equal(key, root.key, comparator)) {
return Null;
} else {
return root;
}
}
stack = new NodeStack(stack);
Node newRoot = getNode(token, root);
Node old = root;
Node new_ = newRoot;
while (old != Null) {
if (key == null) throw new NullPointerException();
if (old.key == null) {
throw new NullPointerException();
}
int difference = Compare.compare(key, old.key, comparator);
if (difference < 0) {
stack.push(new_);
old = old.left;
new_ = new_.left = getNode(token, old);
} else if (difference > 0) {
stack.push(new_);
old = old.right;
new_ = new_.right = getNode(token, old);
} else {
break;
}
}
if (old == Null) {
if (stack.top.left == new_) {
stack.top.left = Null;
} else {
stack.top.right = Null;
}
stack.popStack();
return root;
}
Node dead;
if (new_.left == Null || new_.right == Null) {
dead = new_;
} else {
successor(token, new_, stack);
dead = stack.top;
stack.pop();
}
Node child;
if (dead.left != Null) {
child = getNode(token, dead.left);
} else if (dead.right != Null) {
child = getNode(token, dead.right);
} else {
child = Null;
}
if (stack.top == null) {
child.red = false;
stack.popStack();
if (Debug) {
validate(root, child);
}
return child;
} else if (dead == stack.top.left) {
stack.top.left = child;
} else {
stack.top.right = child;
}
if (dead != new_) {
new_.key = dead.key;
new_.value = dead.value;
}
if (!dead.red) {
// rebalance
while (stack.top != null && !child.red) {
if (Debug) checkArgument(stack.top.token == token);
if (child == stack.top.left) {
Node sibling = stack.top.right = getNode(token, stack.top.right);
if (sibling.red) {
if (Debug) checkArgument(sibling.token == token);
sibling.red = false;
stack.top.red = true;
Node n = leftRotate(token, stack.top);
if (stack.index == stack.base) {
newRoot = n;
} else if (stack.peek().right == stack.top) {
if (Debug) checkArgument(stack.peek().token == token);
stack.peek().right = n;
} else {
if (Debug) checkArgument(stack.peek().token == token);
stack.peek().left = n;
}
Node parent = stack.top;
stack.top = n;
stack.push(parent);
sibling = stack.top.right = getNode(token, stack.top.right);
}
if (!(sibling.left.red || sibling.right.red)) {
if (Debug) checkArgument(sibling.token == token);
sibling.red = true;
child = stack.top;
stack.pop();
} else {
if (!sibling.right.red) {
sibling.left = getNode(token, sibling.left);
sibling.left.red = false;
if (Debug) checkArgument(sibling.token == token);
sibling.red = true;
sibling = stack.top.right = rightRotate(token, sibling);
}
if (Debug) checkArgument(sibling.token == token);
sibling.red = stack.top.red;
stack.top.red = false;
sibling.right = getNode(token, sibling.right);
sibling.right.red = false;
Node n = leftRotate(token, stack.top);
if (stack.index == stack.base) {
newRoot = n;
} else if (stack.peek().right == stack.top) {
if (Debug) checkArgument(stack.peek().token == token);
stack.peek().right = n;
} else {
if (Debug) checkArgument(stack.peek().token == token);
stack.peek().left = n;
}
child = newRoot;
stack.clear();
}
} else {
// this is just the above code with left and right swapped:
Node sibling = stack.top.left = getNode(token, stack.top.left);
if (sibling.red) {
if (Debug) checkArgument(sibling.token == token);
sibling.red = false;
stack.top.red = true;
Node n = rightRotate(token, stack.top);
if (stack.index == stack.base) {
newRoot = n;
} else if (stack.peek().left == stack.top) {
if (Debug) checkArgument(stack.peek().token == token);
stack.peek().left = n;
} else {
if (Debug) checkArgument(stack.peek().token == token);
stack.peek().right = n;
}
Node parent = stack.top;
stack.top = n;
stack.push(parent);
sibling = stack.top.left = getNode(token, stack.top.left);
}
if (!(sibling.right.red || sibling.left.red)) {
if (Debug) checkArgument(sibling.token == token);
sibling.red = true;
child = stack.top;
stack.pop();
} else {
if (!sibling.left.red) {
sibling.right = getNode(token, sibling.right);
sibling.right.red = false;
if (Debug) checkArgument(sibling.token == token);
sibling.red = true;
sibling = stack.top.left = leftRotate(token, sibling);
}
if (Debug) checkArgument(sibling.token == token);
sibling.red = stack.top.red;
stack.top.red = false;
sibling.left = getNode(token, sibling.left);
sibling.left.red = false;
Node n = rightRotate(token, stack.top);
if (stack.index == stack.base) {
newRoot = n;
} else if (stack.peek().left == stack.top) {
if (Debug) checkArgument(stack.peek().token == token);
stack.peek().left = n;
} else {
if (Debug) checkArgument(stack.peek().token == token);
stack.peek().right = n;
}
child = newRoot;
stack.clear();
}
}
}
if (Debug) checkArgument(child.token == token);
child.red = false;
}
stack.popStack();
if (Debug) {
validate(root, newRoot);
}
return newRoot;
}