private static AVLTree balance(AVLTree l, Object key, Object value, AVLTree r) {
if (l.height() > r.height() + 2) {
assert !l.isEmpty();
AVLTree ll = l.left();
AVLTree lr = l.right();
if (ll.height() >= lr.height()) {
return createNode(ll, l, createNode(lr, key, value, r));
}
assert !lr.isEmpty();
AVLTree lrl = lr.left();
AVLTree lrr = lr.right();
return createNode(createNode(ll, l, lrl), lr, createNode(lrr, key, value, r));
}
if (r.height() > l.height() + 2) {
assert !r.isEmpty();
AVLTree rl = r.left();
AVLTree rr = r.right();
if (rr.height() >= rl.height()) {
return createNode(createNode(l, key, value, rl), r, rr);
}
assert !rl.isEmpty();
AVLTree rll = rl.left();
AVLTree rlr = rl.right();
return createNode(createNode(l, key, value, rll), rl, createNode(rlr, r, rr));
}
return createNode(l, key, value, r);
}
private static AVLTree removeMinBinding(AVLTree t, NodeRef noderemoved) {
assert !t.isEmpty();
if (t.left().isEmpty()) {
noderemoved.node = t;
return t.right();
}
return balance(removeMinBinding(t.left(), noderemoved), t.key(), t.value(), t.right());
}
@SuppressWarnings("unchecked")
private void forEach(AVLTree t, PSet.Consumer<K> action) {
if (t.isEmpty()) {
return;
}
action.accept((K) t.key());
forEach(t.left(), action);
forEach(t.right(), action);
}
private static AVLTree remove(Object key, AVLTree t) {
if (t.isEmpty()) {
return t;
}
int result = KEY_COMPARATOR.compare(key, t.key());
if (result == 0) {
return combineTrees(t.left(), t.right());
} else if (result < 0) {
AVLTree left = remove(key, t.left());
if (left == t.left()) {
return t;
}
return balance(left, t.key(), t.value(), t.right());
} else {
AVLTree right = remove(key, t.right());
if (right == t.right()) {
return t;
}
return balance(t.left(), t.key(), t.value(), right);
}
}
private static AVLTree put(Object key, Object value, AVLTree t) {
if (t.isEmpty()) {
return createNode(t, key, value, t);
}
int result = KEY_COMPARATOR.compare(key, t.key());
if (result == 0) {
if (value.equals(t.value())) {
return t;
}
return createNode(t.left(), key, value, t.right());
} else if (result < 0) {
AVLTree left = put(key, value, t.left());
if (left == t.left()) {
return t;
}
return balance(left, t.key(), t.value(), t.right());
} else {
AVLTree right = put(key, value, t.right());
if (right == t.right()) {
return t;
}
return balance(t.left(), t.key(), t.value(), right);
}
}
@SuppressWarnings("unchecked")
@Nullable
@Override
public V get(K key) {
Preconditions.checkNotNull(key);
AVLTree t = this;
while (!t.isEmpty()) {
int c = KEY_COMPARATOR.compare(key, t.key());
if (c == 0) {
return (V) t.value();
} else if (c < 0) {
t = t.left();
} else {
t = t.right();
}
}
return null;
}