/**
* Returns a deep copy of this tree set.
*
* <p>This method performs a deep copy of this tree set; the data stored in the set, however, is
* not cloned. Note that this makes a difference only for object keys.
*
* @return a deep copy of this tree set.
*/
@SuppressWarnings("unchecked")
public Object clone() {
ObjectRBTreeSet<K> c;
try {
c = (ObjectRBTreeSet<K>) super.clone();
} catch (CloneNotSupportedException cantHappen) {
throw new InternalError();
}
c.allocatePaths();
if (count != 0) {
// Also this apparently unfathomable code is derived from GNU libavl.
Entry<K> e, p, q, rp = new Entry<K>(), rq = new Entry<K>();
p = rp;
rp.left(tree);
q = rq;
rq.pred(null);
while (true) {
if (!p.pred()) {
e = p.left.clone();
e.pred(q.left);
e.succ(q);
q.left(e);
p = p.left;
q = q.left;
} else {
while (p.succ()) {
p = p.right;
if (p == null) {
q.right = null;
c.tree = rq.left;
c.firstEntry = c.tree;
while (c.firstEntry.left != null) c.firstEntry = c.firstEntry.left;
c.lastEntry = c.tree;
while (c.lastEntry.right != null) c.lastEntry = c.lastEntry.right;
return c;
}
q = q.right;
}
p = p.right;
q = q.right;
}
if (!p.succ()) {
e = p.right.clone();
e.succ(q.right);
e.pred(q);
q.right(e);
}
}
}
return c;
}
/**
* Reads the given number of entries from the input stream, returning the corresponding tree.
*
* @param s the input stream.
* @param n the (positive) number of entries to read.
* @param pred the entry containing the key that preceeds the first key in the tree.
* @param succ the entry containing the key that follows the last key in the tree.
*/
@SuppressWarnings("unchecked")
private Entry<K> readTree(
final java.io.ObjectInputStream s, final int n, final Entry<K> pred, final Entry<K> succ)
throws java.io.IOException, ClassNotFoundException {
if (n == 1) {
final Entry<K> top = new Entry<K>((K) s.readObject());
top.pred(pred);
top.succ(succ);
top.black(true);
return top;
}
if (n == 2) {
/* We handle separately this case so that recursion will
*always* be on nonempty subtrees. */
final Entry<K> top = new Entry<K>((K) s.readObject());
top.black(true);
top.right(new Entry<K>((K) s.readObject()));
top.right.pred(top);
top.pred(pred);
top.right.succ(succ);
return top;
}
// The right subtree is the largest one.
final int rightN = n / 2, leftN = n - rightN - 1;
final Entry<K> top = new Entry<K>();
top.left(readTree(s, leftN, pred, top));
top.key = (K) s.readObject();
top.black(true);
top.right(readTree(s, rightN, top, succ));
if (n + 2 == ((n + 2) & -(n + 2)))
top.right.black(false); // Quick test for determining whether n + 2 is a power of 2.
return top;
}
/**
* Ensures that this BinarySearchTree object contains a specified element. The worstTime(n) is
* O(n) and averageTime(n) is O(log n).
*
* @param element - the element whose presence is ensured in this BinarySearchTree object.
* @return true - if this BinarySearchTree object changed as a result of this method call (that
* is, if element was actually inserted); otherwise, return false.
* @throws ClassCastException - if element cannot be compared to the elements already in this
* BinarySearchTree object.
* @throws NullPointerException - if element is null.
*/
public boolean add(E element) {
if (root == null) {
if (element == null) throw new NullPointerException();
root = new Entry<E>(element, null);
size++;
return true;
} // empty tree
else {
Entry<E> temp = root;
int comp;
while (true) {
comp = ((Comparable) element).compareTo(temp.element);
if (comp == 0) return false;
if (comp < 0)
if (temp.left != null) temp = temp.left;
else {
temp.left = new Entry<E>(element, temp);
size++;
return true;
} // temp.left == null
else if (temp.right != null) temp = temp.right;
else {
temp.right = new Entry<E>(element, temp);
size++;
return true;
} // temp.right == null
} // while
} // root not null
} // method add
/**
* Returns the entry corresponding to the given key, if it is in the tree; <code>null</code>,
* otherwise.
*
* @param k the key to search for.
* @return the corresponding entry, or <code>null</code> if no entry with the given key exists.
*/
private Entry<K> findKey(final K k) {
Entry<K> e = tree;
int cmp;
while (e != null && (cmp = compare(k, e.key)) != 0) e = cmp < 0 ? e.left() : e.right();
return e;
}
protected Entry<E> copy(Entry<? extends E> p, Entry<E> parent) {
if (p != null) {
Entry<E> q = new Entry<E>(p.element, parent);
q.left = copy(p.left, q);
q.right = copy(p.right, q);
return q;
} // if
return null;
} // method copy
private void readObject(java.io.ObjectInputStream s)
throws java.io.IOException, ClassNotFoundException {
s.defaultReadObject();
/* The storedComparator is now correctly set, but we must restore
on-the-fly the actualComparator. */
setActualComparator();
allocatePaths();
if (count != 0) {
tree = readTree(s, count, null, null);
Entry<K> e;
e = tree;
while (e.left() != null) e = e.left();
firstEntry = e;
e = tree;
while (e.right() != null) e = e.right();
lastEntry = e;
}
if (ASSERTS) checkTree(tree, 0, -1);
}
/**
* Locates a key.
*
* @param k a key.
* @return the last entry on a search for the given key; this will be the given key, if it
* present; otherwise, it will be either the smallest greater key or the greatest smaller key.
*/
final Entry<K> locateKey(final K k) {
Entry<K> e = tree, last = tree;
int cmp = 0;
while (e != null && (cmp = compare(k, e.key)) != 0) {
last = e;
e = cmp < 0 ? e.left() : e.right();
}
return cmp == 0 ? e : last;
}
@SuppressWarnings("unchecked")
public boolean remove(final Object k) {
if (tree == null) return false;
Entry<K> p = tree;
int cmp;
int i = 0;
final K kk = (K) k;
while (true) {
if ((cmp = compare(kk, p.key)) == 0) break;
dirPath[i] = cmp > 0;
nodePath[i] = p;
if (dirPath[i++]) {
if ((p = p.right()) == null) {
// We clean up the node path, or we could have stale references later.
while (i-- != 0) nodePath[i] = null;
return false;
}
} else {
if ((p = p.left()) == null) {
// We clean up the node path, or we could have stale references later.
while (i-- != 0) nodePath[i] = null;
return false;
}
}
}
if (p.left == null) firstEntry = p.next();
if (p.right == null) lastEntry = p.prev();
if (p.succ()) {
if (p.pred()) {
if (i == 0) tree = p.left;
else {
if (dirPath[i - 1]) nodePath[i - 1].succ(p.right);
else nodePath[i - 1].pred(p.left);
}
} else {
p.prev().right = p.right;
if (i == 0) tree = p.left;
else {
if (dirPath[i - 1]) nodePath[i - 1].right = p.left;
else nodePath[i - 1].left = p.left;
}
}
} else {
boolean color;
Entry<K> r = p.right;
if (r.pred()) {
r.left = p.left;
r.pred(p.pred());
if (!r.pred()) r.prev().right = r;
if (i == 0) tree = r;
else {
if (dirPath[i - 1]) nodePath[i - 1].right = r;
else nodePath[i - 1].left = r;
}
color = r.black();
r.black(p.black());
p.black(color);
dirPath[i] = true;
nodePath[i++] = r;
} else {
Entry<K> s;
int j = i++;
while (true) {
dirPath[i] = false;
nodePath[i++] = r;
s = r.left;
if (s.pred()) break;
r = s;
}
dirPath[j] = true;
nodePath[j] = s;
if (s.succ()) r.pred(s);
else r.left = s.right;
s.left = p.left;
if (!p.pred()) {
p.prev().right = s;
s.pred(false);
}
s.right(p.right);
color = s.black();
s.black(p.black());
p.black(color);
if (j == 0) tree = s;
else {
if (dirPath[j - 1]) nodePath[j - 1].right = s;
else nodePath[j - 1].left = s;
}
}
}
int maxDepth = i;
if (p.black()) {
for (; i > 0; i--) {
if (dirPath[i - 1] && !nodePath[i - 1].succ()
|| !dirPath[i - 1] && !nodePath[i - 1].pred()) {
Entry<K> x = dirPath[i - 1] ? nodePath[i - 1].right : nodePath[i - 1].left;
if (!x.black()) {
x.black(true);
break;
}
}
if (!dirPath[i - 1]) {
Entry<K> w = nodePath[i - 1].right;
if (!w.black()) {
w.black(true);
nodePath[i - 1].black(false);
nodePath[i - 1].right = w.left;
w.left = nodePath[i - 1];
if (i < 2) tree = w;
else {
if (dirPath[i - 2]) nodePath[i - 2].right = w;
else nodePath[i - 2].left = w;
}
nodePath[i] = nodePath[i - 1];
dirPath[i] = false;
nodePath[i - 1] = w;
if (maxDepth == i++) maxDepth++;
w = nodePath[i - 1].right;
}
if ((w.pred() || w.left.black()) && (w.succ() || w.right.black())) {
w.black(false);
} else {
if (w.succ() || w.right.black()) {
Entry<K> y = w.left;
y.black(true);
w.black(false);
w.left = y.right;
y.right = w;
w = nodePath[i - 1].right = y;
if (w.succ()) {
w.succ(false);
w.right.pred(w);
}
}
w.black(nodePath[i - 1].black());
nodePath[i - 1].black(true);
w.right.black(true);
nodePath[i - 1].right = w.left;
w.left = nodePath[i - 1];
if (i < 2) tree = w;
else {
if (dirPath[i - 2]) nodePath[i - 2].right = w;
else nodePath[i - 2].left = w;
}
if (w.pred()) {
w.pred(false);
nodePath[i - 1].succ(w);
}
break;
}
} else {
Entry<K> w = nodePath[i - 1].left;
if (!w.black()) {
w.black(true);
nodePath[i - 1].black(false);
nodePath[i - 1].left = w.right;
w.right = nodePath[i - 1];
if (i < 2) tree = w;
else {
if (dirPath[i - 2]) nodePath[i - 2].right = w;
else nodePath[i - 2].left = w;
}
nodePath[i] = nodePath[i - 1];
dirPath[i] = true;
nodePath[i - 1] = w;
if (maxDepth == i++) maxDepth++;
w = nodePath[i - 1].left;
}
if ((w.pred() || w.left.black()) && (w.succ() || w.right.black())) {
w.black(false);
} else {
if (w.pred() || w.left.black()) {
Entry<K> y = w.right;
y.black(true);
w.black(false);
w.right = y.left;
y.left = w;
w = nodePath[i - 1].left = y;
if (w.pred()) {
w.pred(false);
w.left.succ(w);
}
}
w.black(nodePath[i - 1].black());
nodePath[i - 1].black(true);
w.left.black(true);
nodePath[i - 1].left = w.right;
w.right = nodePath[i - 1];
if (i < 2) tree = w;
else {
if (dirPath[i - 2]) nodePath[i - 2].right = w;
else nodePath[i - 2].left = w;
}
if (w.succ()) {
w.succ(false);
nodePath[i - 1].pred(w);
}
break;
}
}
}
if (tree != null) tree.black(true);
}
count--;
// We clean up the node path, or we could have stale references later.
while (maxDepth-- != 0) nodePath[maxDepth] = null;
if (ASSERTS) {
checkNodePath();
checkTree(tree, 0, -1);
}
return true;
}
public boolean add(final K k) {
int maxDepth = 0;
if (tree == null) { // The case of the empty tree is treated separately.
count++;
tree = lastEntry = firstEntry = new Entry<K>(k);
} else {
Entry<K> p = tree, e;
int cmp, i = 0;
while (true) {
if ((cmp = compare(k, p.key)) == 0) {
// We clean up the node path, or we could have stale references later.
while (i-- != 0) nodePath[i] = null;
return false;
}
nodePath[i] = p;
if (dirPath[i++] = cmp > 0) {
if (p.succ()) {
count++;
e = new Entry<K>(k);
if (p.right == null) lastEntry = e;
e.left = p;
e.right = p.right;
p.right(e);
break;
}
p = p.right;
} else {
if (p.pred()) {
count++;
e = new Entry<K>(k);
if (p.left == null) firstEntry = e;
e.right = p;
e.left = p.left;
p.left(e);
break;
}
p = p.left;
}
}
maxDepth = i--;
while (i > 0 && !nodePath[i].black()) {
if (!dirPath[i - 1]) {
Entry<K> y = nodePath[i - 1].right;
if (!nodePath[i - 1].succ() && !y.black()) {
nodePath[i].black(true);
y.black(true);
nodePath[i - 1].black(false);
i -= 2;
} else {
Entry<K> x;
if (!dirPath[i]) y = nodePath[i];
else {
x = nodePath[i];
y = x.right;
x.right = y.left;
y.left = x;
nodePath[i - 1].left = y;
if (y.pred()) {
y.pred(false);
x.succ(y);
}
}
x = nodePath[i - 1];
x.black(false);
y.black(true);
x.left = y.right;
y.right = x;
if (i < 2) tree = y;
else {
if (dirPath[i - 2]) nodePath[i - 2].right = y;
else nodePath[i - 2].left = y;
}
if (y.succ()) {
y.succ(false);
x.pred(y);
}
break;
}
} else {
Entry<K> y = nodePath[i - 1].left;
if (!nodePath[i - 1].pred() && !y.black()) {
nodePath[i].black(true);
y.black(true);
nodePath[i - 1].black(false);
i -= 2;
} else {
Entry<K> x;
if (dirPath[i]) y = nodePath[i];
else {
x = nodePath[i];
y = x.left;
x.left = y.right;
y.right = x;
nodePath[i - 1].right = y;
if (y.succ()) {
y.succ(false);
x.pred(y);
}
}
x = nodePath[i - 1];
x.black(false);
y.black(true);
x.right = y.left;
y.left = x;
if (i < 2) tree = y;
else {
if (dirPath[i - 2]) nodePath[i - 2].right = y;
else nodePath[i - 2].left = y;
}
if (y.pred()) {
y.pred(false);
x.succ(y);
}
break;
}
}
}
}
tree.black(true);
// We clean up the node path, or we could have stale references later.
while (maxDepth-- != 0) nodePath[maxDepth] = null;
if (ASSERTS) {
checkNodePath();
checkTree(tree, 0, -1);
}
return true;
}
@SuppressWarnings("unchecked")
public boolean remove(final long k) {
if (tree == null) return false;
int cmp;
Entry p = tree, q = null;
boolean dir = false;
final long kk = k;
while (true) {
if ((cmp = compare(kk, p.key)) == 0) break;
else if (dir = cmp > 0) {
q = p;
if ((p = p.right()) == null) return false;
} else {
q = p;
if ((p = p.left()) == null) return false;
}
}
if (p.left == null) firstEntry = p.next();
if (p.right == null) lastEntry = p.prev();
if (p.succ()) {
if (p.pred()) {
if (q != null) {
if (dir) q.succ(p.right);
else q.pred(p.left);
} else tree = dir ? p.right : p.left;
} else {
p.prev().right = p.right;
if (q != null) {
if (dir) q.right = p.left;
else q.left = p.left;
} else tree = p.left;
}
} else {
Entry r = p.right;
if (r.pred()) {
r.left = p.left;
r.pred(p.pred());
if (!r.pred()) r.prev().right = r;
if (q != null) {
if (dir) q.right = r;
else q.left = r;
} else tree = r;
r.balance(p.balance());
q = r;
dir = true;
} else {
Entry s;
while (true) {
s = r.left;
if (s.pred()) break;
r = s;
}
if (s.succ()) r.pred(s);
else r.left = s.right;
s.left = p.left;
if (!p.pred()) {
p.prev().right = s;
s.pred(false);
}
s.right = p.right;
s.succ(false);
if (q != null) {
if (dir) q.right = s;
else q.left = s;
} else tree = s;
s.balance(p.balance());
q = r;
dir = false;
}
}
Entry y;
while (q != null) {
y = q;
q = parent(y);
if (!dir) {
dir = q != null && q.left != y;
y.incBalance();
if (y.balance() == 1) break;
else if (y.balance() == 2) {
Entry x = y.right;
if (ASSERTS) assert x != null;
if (x.balance() == -1) {
Entry w;
if (ASSERTS) assert x.balance() == -1;
w = x.left;
x.left = w.right;
w.right = x;
y.right = w.left;
w.left = y;
if (w.balance() == 1) {
x.balance(0);
y.balance(-1);
} else if (w.balance() == 0) {
x.balance(0);
y.balance(0);
} else {
if (ASSERTS) assert w.balance() == -1;
x.balance(1);
y.balance(0);
}
w.balance(0);
if (w.pred()) {
y.succ(w);
w.pred(false);
}
if (w.succ()) {
x.pred(w);
w.succ(false);
}
if (q != null) {
if (dir) q.right = w;
else q.left = w;
} else tree = w;
} else {
if (q != null) {
if (dir) q.right = x;
else q.left = x;
} else tree = x;
if (x.balance() == 0) {
y.right = x.left;
x.left = y;
x.balance(-1);
y.balance(+1);
break;
}
if (ASSERTS) assert x.balance() == 1;
if (x.pred()) {
y.succ(true);
x.pred(false);
} else y.right = x.left;
x.left = y;
y.balance(0);
x.balance(0);
}
}
} else {
dir = q != null && q.left != y;
y.decBalance();
if (y.balance() == -1) break;
else if (y.balance() == -2) {
Entry x = y.left;
if (ASSERTS) assert x != null;
if (x.balance() == 1) {
Entry w;
if (ASSERTS) assert x.balance() == 1;
w = x.right;
x.right = w.left;
w.left = x;
y.left = w.right;
w.right = y;
if (w.balance() == -1) {
x.balance(0);
y.balance(1);
} else if (w.balance() == 0) {
x.balance(0);
y.balance(0);
} else {
if (ASSERTS) assert w.balance() == 1;
x.balance(-1);
y.balance(0);
}
w.balance(0);
if (w.pred()) {
x.succ(w);
w.pred(false);
}
if (w.succ()) {
y.pred(w);
w.succ(false);
}
if (q != null) {
if (dir) q.right = w;
else q.left = w;
} else tree = w;
} else {
if (q != null) {
if (dir) q.right = x;
else q.left = x;
} else tree = x;
if (x.balance() == 0) {
y.left = x.right;
x.right = y;
x.balance(+1);
y.balance(-1);
break;
}
if (ASSERTS) assert x.balance() == -1;
if (x.succ()) {
y.pred(true);
x.succ(false);
} else y.left = x.right;
x.right = y;
y.balance(0);
x.balance(0);
}
}
}
}
count--;
if (ASSERTS) checkTree(tree);
return true;
}
public boolean add(final long k) {
if (tree == null) { // The case of the empty tree is treated separately.
count++;
tree = lastEntry = firstEntry = new Entry(k);
} else {
Entry p = tree, q = null, y = tree, z = null, e = null, w = null;
int cmp, i = 0;
while (true) {
if ((cmp = compare(k, p.key)) == 0) return false;
if (p.balance() != 0) {
i = 0;
z = q;
y = p;
}
if (dirPath[i++] = cmp > 0) {
if (p.succ()) {
count++;
e = new Entry(k);
if (p.right == null) lastEntry = e;
e.left = p;
e.right = p.right;
p.right(e);
break;
}
q = p;
p = p.right;
} else {
if (p.pred()) {
count++;
e = new Entry(k);
if (p.left == null) firstEntry = e;
e.right = p;
e.left = p.left;
p.left(e);
break;
}
q = p;
p = p.left;
}
}
p = y;
i = 0;
while (p != e) {
if (dirPath[i]) p.incBalance();
else p.decBalance();
p = dirPath[i++] ? p.right : p.left;
}
if (y.balance() == -2) {
Entry x = y.left;
if (x.balance() == -1) {
w = x;
if (x.succ()) {
x.succ(false);
y.pred(x);
} else y.left = x.right;
x.right = y;
x.balance(0);
y.balance(0);
} else {
if (ASSERTS) assert x.balance() == 1;
w = x.right;
x.right = w.left;
w.left = x;
y.left = w.right;
w.right = y;
if (w.balance() == -1) {
x.balance(0);
y.balance(1);
} else if (w.balance() == 0) {
x.balance(0);
y.balance(0);
} else {
x.balance(-1);
y.balance(0);
}
w.balance(0);
if (w.pred()) {
x.succ(w);
w.pred(false);
}
if (w.succ()) {
y.pred(w);
w.succ(false);
}
}
} else if (y.balance() == +2) {
Entry x = y.right;
if (x.balance() == 1) {
w = x;
if (x.pred()) {
x.pred(false);
y.succ(x);
} else y.right = x.left;
x.left = y;
x.balance(0);
y.balance(0);
} else {
if (ASSERTS) assert x.balance() == -1;
w = x.left;
x.left = w.right;
w.right = x;
y.right = w.left;
w.left = y;
if (w.balance() == 1) {
x.balance(0);
y.balance(-1);
} else if (w.balance() == 0) {
x.balance(0);
y.balance(0);
} else {
x.balance(1);
y.balance(0);
}
w.balance(0);
if (w.pred()) {
y.succ(w);
w.pred(false);
}
if (w.succ()) {
x.pred(w);
w.succ(false);
}
}
} else return true;
if (z == null) tree = w;
else {
if (z.left == y) z.left = w;
else z.right = w;
}
}
if (ASSERTS) checkTree(tree);
return true;
}