protected final Decision doTraverse(Node<K, V> top, Cursor<? super K, ? super V> cursor) {
if (top.isInternal()) {
Decision d = doTraverse(top.left(ctx()), cursor);
switch (d) {
case REMOVE_AND_EXIT: // fall through
case EXIT:
return Decision.EXIT;
case REMOVE: // fall through
case CONTINUE:
default:
return doTraverse(top.right(ctx()), cursor);
}
} else {
Map.Entry<K, V> e = AbstractCritBitTree.<Map.Entry<K, V>>cast(top);
return cursor.select(e);
}
}
@Override
public Entry<K, V> next() {
return AbstractCritBitTree.<Entry<K, V>>cast(base.next());
}
public V remove(Object k) {
if (root == null) {
return null;
}
final K key = AbstractCritBitTree.<K>cast(k);
if (!root.isInternal()) {
if (ctx().chk.bitIndex(key, root.getKey()) < 0) {
V out = root.getValue();
root = null;
size--;
return out;
} else {
return null;
}
}
Node<K, V> grandparent = null;
Node<K, V> parent = null;
Node<K, V> cur = root;
for (; ; ) {
switch (cur.next(key, ctx())) {
case LEFT:
if (cur.hasExternalLeft()) {
Node<K, V> leftNode = cur.left(ctx());
if (ctx().chk.bitIndex(key, leftNode.getKey()) < 0) {
if (grandparent == null) {
root = root.remove(key, ctx(), true);
} else {
grandparent.remove(key, ctx(), true);
}
size--;
return leftNode.getValue();
} else {
return null;
}
}
grandparent = parent;
parent = cur;
cur = cur.left(ctx());
break;
case RIGHT:
if (cur.hasExternalRight()) {
Node<K, V> rightNode = cur.right(ctx());
if (ctx().chk.bitIndex(key, rightNode.getKey()) < 0) {
if (grandparent == null) {
root = root.remove(key, ctx(), true);
} else {
grandparent.remove(key, ctx(), true);
}
size--;
return rightNode.getValue();
} else {
return null;
}
}
grandparent = parent;
parent = cur;
cur = cur.right(ctx());
break;
}
}
}