/* priorityqueue.vala
*
* Copyright (C) 2009 Didier Villevalois
* Copyright (C) 2012-2014 Maciej Piechotka
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
* Author:
* Didier 'Ptitjes Villevalois <ptitjes@free.fr>
*/
/**
* Relaxed fibonacci heap priority queue implementation of the {@link Queue}.
*
* The elements of the priority queue are ordered according to their natural
* ordering, or by a compare_func provided at queue construction time. A
* priority queue does not permit null elements and does not have bounded
* capacity.
*
* This implementation provides O(1) time for offer and peek methods, and
* O(log n) for poll method. It is based on the algorithms described by
* Boyapati Chandra Sekhar in:
*
* "Worst Case Efficient Data Structures
* for Priority Queues and Deques with Heap Order"
* Boyapati Chandra Sekhar (under the guidance of Prof. C. Pandu Rangan)
* Department of Computer Science and Engineering
* Indian Institute of Technology, Madras
* May 1996
*/
public class Gee.PriorityQueue<G> : Gee.AbstractQueue<G> {
/**
* The elements' comparator function.
*/
[CCode (notify = false)]
public CompareDataFunc<G> compare_func {
private set {}
get {
return _compare_func;
}
}
private int _size = 0;
private int _stamp = 0;
private Type1Node<G>? _r = null;
private Type2Node<G>? _r_prime = null;
private Type2Node<G>? _lm_head = null;
private Type2Node<G>? _lm_tail = null;
private Type1Node<G>? _p = null;
private Type1Node<G>?[] _a;
private NodePair<G>? _lp_head = null;
private unowned NodePair<G>? _lp_tail = null;
private bool[] _b = new bool[0];
private Type1Node<G>? _ll_head = null;
private Type1Node<G>? _ll_tail = null;
private unowned Node<G> _iter_head = null;
private unowned Node<G> _iter_tail = null;
private CompareDataFunc<G> _compare_func;
/**
* Constructs a new, empty priority queue.
*
* If not provided, the function parameter is requested to the
* {@link Functions} function factory methods.
*
* @param compare_func an optional element comparator function
*/
public PriorityQueue (owned CompareDataFunc<G>? compare_func = null) {
if (compare_func == null) {
compare_func = Functions.get_compare_func_for (typeof (G));
}
_compare_func = (owned)compare_func;
_a = new Type1Node<G>?[0];
}
/**
* {@inheritDoc}
*/
public override int capacity {
get { return UNBOUNDED_CAPACITY; }
}
/**
* {@inheritDoc}
*/
public override int remaining_capacity {
get { return UNBOUNDED_CAPACITY; }
}
/**
* {@inheritDoc}
*/
public override bool is_full {
get { return false; }
}
/**
* {@inheritDoc}
*/
public override bool read_only {
get { return false; }
}
/**
* {@inheritDoc}
*/
public bool offer (G element) {
#if DEBUG
_dump ("Start offer: %s".printf ((string)element));
#endif
if (_r == null) {
_r = new Type1Node<G> (element, ref _iter_head, ref _iter_tail);
_p = _r;
} else if (_r_prime == null) {
_r_prime = new Type2Node<G> (element, ref _iter_head, ref _iter_tail);
_r_prime.parent = _r;
_r.type2_child = _r_prime;
if (_compare (_r_prime, _r) < 0)
_swap_data (_r_prime, _r);
} else {
// Form a tree with a single node N of type I consisting of element e
Type1Node<G> node = new Type1Node<G> (element, ref _iter_head, ref _iter_tail);
//Add(Q, N)
_add (node);
}
_stamp++;
_size++;
#if DEBUG
_dump ("End offer: %s".printf ((string)element));
#endif
return true;
}
/**
* {@inheritDoc}
*/
public override G? peek () {
if (_r == null) {
return null;
}
return _r.data;
}
/**
* {@inheritDoc}
*/
public override G? poll () {
#if DEBUG
_dump ("Start poll:");
#endif
// 1a. M inElement <- R.element
if (_r == null) {
return null;
}
G min = _r.data;
_r.pending_drop = false;
_stamp++;
_size--;
// 1b. R.element = R'.element
if (_r_prime == null) {
if (_r.iter_next != null) {
_r.iter_next.iter_prev = _r.iter_prev;
}
if (_r.iter_prev != null) {
_r.iter_prev.iter_next = _r.iter_next;
}
if (_iter_head == _r) {
_iter_head = _r.iter_next;
}
if (_iter_tail == _r) {
_iter_tail = _r.iter_prev;
}
_r = null;
_p = null;
return min;
}
_move_data (_r, _r_prime);
// 1c. R'' <- The child of R' containing the minimum element among the children of R'
if (_r_prime.type1_children_head == null) {
_remove_type2_node (_r_prime, true);
_r_prime = null;
return min;
}
Type1Node<G>? r_second = null;
Type1Node<G> node = _r_prime.type1_children_head;
while (node != null) {
if (r_second == null || _compare (node, r_second) < 0) {
r_second = node;
}
node = node.brothers_next;
}
// 1d. R'.element <- R''.element
_move_data (_r_prime, r_second);
// 2a. Delete the subtree rooted at R'' from Q
_remove_type1_node (r_second, true);
// 2b. For all children N of type I of R'' do make N a child of R' of Q
node = r_second.type1_children_head;
while (node != null) {
Type1Node<G> next = node.brothers_next;
_remove_type1_node (node, false);
_add_in_r_prime (node);
node = next;
}
// For now we can't have type2 node other than R' (left for reference)
#if false
// 3a. If R'' has no child of type II then goto Step 4.
if (r_second.type2_child != null) {
// 3b. Let M' be the child of type II of R''. Insert(Q, M'.element)
Type2Node<G> m_prime = r_second.type2_child;
_remove_type2_node (m_prime);
offer (m_prime.data);
// 3c. For all children N of M do make N a child of R' of Q
node = m_prime.type1_children_head;
while (node != null) {
Type1Node<G> next = node.brothers_next;
_remove_type1_node (node);
_add_in_r_prime (node);
node = next;
}
}
#endif
// 4. Adjust(Q, P, P)
_adjust (_p, _p);
// For now we can't have type2 node other than R' (left for reference)
#if false
// 5a. if LM is empty then goto Step 6
if (_lm_head != null) {
// 5b. M <- Head(LM); LM <- Tail(LM)
Type2Node<G> m = _lm_head;
// 5c. Delete M from Q
_remove_type2_node (m);
// 5d. I nsert(Q, M.element)
offer (m.data);
// 5e. For all children N of M do make M a child of R' of Q
node = m.type1_children_head;
while (node != null) {
Type1Node<G> next = node.brothers_next;
_remove_type1_node (node);
_add_in_r_prime (node);
node = next;
}
}
#endif
// 6. While among the children of R' there exist any two different nodes Ri and Rj
// such that Ri.degree = Rj.degree do Link(Q, Ri, Rj)
while (_check_linkable ()) {}
// 7. Return MinElement
return min;
}
/**
* {@inheritDoc}
*/
public int drain (Collection<G> recipient, int amount = -1) {
if (amount == -1) {
amount = this._size;
}
for (int i = 0; i < amount; i++) {
if (this._size == 0) {
return i;
}
recipient.add (poll ());
}
return amount;
}
/**
* {@inheritDoc}
*/
public override int size {
get { return _size; }
}
/**
* {@inheritDoc}
*/
public override bool contains (G item) {
foreach (G an_item in this) {
if (compare_func (item, an_item) == 0) {
return true;
}
}
return false;
}
/**
* {@inheritDoc}
*/
public override bool add (G item) {
return offer (item);
}
/**
* {@inheritDoc}
*/
public override bool remove (G item) {
#if DEBUG
_dump ("Start remove: %s".printf ((string) item));
#endif
Iterator<G> iterator = new Iterator<G> (this);
while (iterator.next ()) {
G an_item = iterator.get ();
if (compare_func (item, an_item) == 0) {
iterator.remove ();
return true;
}
}
return false;
}
/**
* {@inheritDoc}
*/
public override void clear () {
_size = 0;
_r = null;
_r_prime = null;
_lm_head = null;
_lm_tail = null;
_p = null;
_a = new Type1Node<G>?[0];
_lp_head = null;
_lp_tail = null;
_b = new bool[0];
_ll_head = null;
_ll_tail = null;
_iter_head = null;
_iter_tail = null;
}
/**
* {@inheritDoc}
*/
public override Gee.Iterator<G> iterator () {
return new Iterator<G> (this);
}
/**
* {@inheritDoc}
*/
public override bool foreach (ForallFunc<G> f) {
for (unowned Node<G>? current = _iter_head; current != null; current = current.iter_next) {
if (!f (current.data)) {
return false;
}
}
return true;
}
private inline int _compare (Node<G> node1, Node<G> node2) {
// Assume there can't be two nodes pending drop
if (node1.pending_drop) {
return -1;
} else if (node2.pending_drop) {
return 1;
} else {
return compare_func (node1.data, node2.data);
}
}
private inline void _swap_data (Node<G> node1, Node<G> node2) {
#if DEBUG
_dump ("Before swap: %p(%s) %p(%s)".printf(node1, (string)node1.data, node2, (string)node2.data));
#endif
G temp_data = (owned) node1.data;
bool temp_pending_drop = node1.pending_drop;
node1.data = (owned) node2.data;
node1.pending_drop = node2.pending_drop;
node2.data = (owned) temp_data;
node2.pending_drop = temp_pending_drop;
if (node1.iter_next == node2) { // Before swap: N1 N2
unowned Node<G> temp_iter_prev = node1.iter_prev;
unowned Node<G> temp_iter_next = node2.iter_next;
node1.iter_prev = node2;
node1.iter_next = temp_iter_next;
node2.iter_prev = temp_iter_prev;
node2.iter_next = node1;
} else if (node1.iter_prev == node2) { // Before swap: N2 N1
unowned Node<G> temp_iter_prev = node2.iter_prev;
unowned Node<G> temp_iter_next = node1.iter_next;
node1.iter_prev = temp_iter_prev;
node1.iter_next = node2;
node2.iter_prev = node1;
node2.iter_next = temp_iter_next;
} else {
unowned Node<G> temp_iter_prev = node1.iter_prev;
unowned Node<G> temp_iter_next = node1.iter_next;
node1.iter_prev = node2.iter_prev;
node1.iter_next = node2.iter_next;
node2.iter_prev = temp_iter_prev;
node2.iter_next = temp_iter_next;
}
if (node2 == _iter_head) {
_iter_head = node1;
} else if (node1 == _iter_head) {
_iter_head = node2;
}
if (node2 == _iter_tail) {
_iter_tail = node1;
} else if (node1 == _iter_tail) {
_iter_tail = node2;
}
if (node1.iter_prev != null) {
node1.iter_prev.iter_next = node1;
}
if (node1.iter_next != null) {
node1.iter_next.iter_prev = node1;
}
if (node2.iter_prev != null) {
node2.iter_prev.iter_next = node2;
}
if (node2.iter_next != null) {
node2.iter_next.iter_prev = node2;
}
#if DEBUG
_dump ("After swap: %p(%s) %p(%s)".printf(node1, (string)node1.data, node2, (string)node2.data));
#endif
}
private inline void _move_data (Node<G> target, Node<G> source) {
#if DEBUG
_dump ("Before move: %p(%s) <- %p(%s)".printf(target, (string)target.data, source, (string)source.data));
#endif
if (target.iter_next != null) {
target.iter_next.iter_prev = target.iter_prev;
} else if (_iter_tail == target) {
_iter_tail = target.iter_prev;
}
if (target.iter_prev != null) {
target.iter_prev.iter_next = target.iter_next;
} else if (_iter_head == target) {
_iter_head = target.iter_next;
}
target.data = source.data;
target.pending_drop = source.pending_drop;
target.iter_next = source.iter_next;
target.iter_prev = source.iter_prev;
source.iter_next = null;
source.iter_prev = null;
if (target.iter_next != null) {
target.iter_next.iter_prev = target;
} else if (_iter_tail == source) {
_iter_tail = target;
}
if (target.iter_prev != null) {
target.iter_prev.iter_next = target;
} else if (_iter_head == source) {
_iter_head = target;
}
#if DEBUG
_dump ("After move:");
#endif
}
private void _link (owned Type1Node<G> ri, owned Type1Node<G> rj) {
assert (ri.degree () == rj.degree ());
// Delete the subtrees rooted at Ri and Rj from Q
_remove_type1_node (ri, false);
_remove_type1_node (rj, false);
// If Ri.element > Rj.element then Swap(Ri,Rj)
if (_compare (ri, rj) > 0) {
Type1Node<G> temp = ri;
ri = rj;
rj = temp;
}
// Make Rj the last child of Ri
_add_to (rj, ri);
// Make Ri (whose degree now = d+1) a child of R' of Q
_add_in_r_prime (ri);
}
private void _add (Type1Node<G> n) {
// Make N a child of R' of Q
_add_in_r_prime (n);
// If N.element < R'.element then Swap(N.element, R'.element)
if (_compare (n, _r_prime) < 0) {
_swap_data (n, _r_prime);
}
// If R'.element < R.element then Swap(R'.element, R.element)
if (_compare (_r_prime, _r) < 0) {
_swap_data (_r_prime, _r);
}
// If among the children of R' there exist any two different nodes Ri and Rj
// such that Ri.degree = Rj.degree then Link(Q, Ri, Rj)
_check_linkable ();
#if DEBUG
_dump ("End _add: %p(%s)".printf (n, (string) n.data));
#endif
}
private bool _check_linkable () {
#if DEBUG
_dump ("Start _check_linkable:");
#endif
if (_lp_head != null) {
unowned NodePair<G> pair = _lp_head;
_link (pair.node1, pair.node2);
return true;
}
return false;
}
private Node<G> _re_insert (owned Type1Node<G> n) {
assert (n != _r);
#if DEBUG
_dump ("Start _re_insert: %p(%s)".printf (n, (string) n.data));
#endif
//Parent <- N.parent
Node<G> parent = n.parent;
// Delete the subtree rooted at N from Q
_remove_type1_node (n, false);
// Add(Q, N)
_add (n);
// Return Parent
return parent;
}
private void _adjust (Type1Node<G> p1, Type1Node<G> p2) {
// If M.lost <= 1 for all nodes M in Q then return
if (_ll_head == null) {
return;
}
#if DEBUG
_dump ("Start _adjust: %p(%s), %p(%s)".printf (p1, (string) p1.data, p2, (string) p2.data));
#endif
// If P1.lost > P2.lost then M <- P1 else M <- P2
Type1Node<G> m;
if (p1.lost > p2.lost) {
m = p1;
} else {
m = p2;
}
// If M.lost <= 1 then M <- M' for some node M' in Q such that M'.lost > 1
if (m.lost <= 1) {
m = _ll_head;
if (_ll_head.ll_next != null) {
_ll_head.ll_next.ll_prev = null;
}
_ll_head = _ll_head.ll_next;
}
// P <- ReInsert(Q, M)
_p = (Type1Node<G>) _re_insert (m);
#if DEBUG
_dump ("End _adjust: %p(%s), %p(%s)".printf (p1, (string) p1.data, p2, (string) p2.data));
#endif
}
private void _delete (Node<G> n) {
// DecreaseKey(Q, N, infinite)
_decrease_key (n);
// DeleteMin(Q)
poll ();
}
private void _decrease_key (Node<G> n) {
#if DEBUG
_dump ("Start _decrease_key: %p(%s)".printf (n, (string) n.data));
#endif
if (n == _r || _r_prime == null) {
return;
}
n.pending_drop = true;
// If (N = R or R') and (R'.element < R.element) then
// Swap(R'.element, R.element); return
if (n == _r_prime && _compare (_r_prime, _r) < 0) {
_swap_data (_r_prime, _r);
return;
}
// For now we can't have type2 node other than R' (left for reference)
#if false
// If (N is of type II) and (N.element < N.parent.element) then
// Swap(N.element, N.parent.element); N <- N.parent
if (n is Type2Node && _compare (n, n.parent) < 0) {
_swap_data (n, n.parent);
n = n.parent;
}
#endif
// Can't occur as we made n be the most little (left for reference)
#if false
// If N.element >= N.parent.element then return
if (n.parent != null && _compare (n, n.parent) >= 0) {
return;
}
#endif
// P' <- ReInsert(Q, N)
Node<G> p_prime = _re_insert ((Type1Node<G>) n);
if (p_prime is Type2Node) {
// Adjust(Q, P, P);
_adjust (_p, _p);
} else {
// Adjust(Q, P, P');
_adjust (_p, (Type1Node<G>) p_prime);
}
}
private void _add_to (Type1Node<G> node, Type1Node<G> parent) {
parent.add (node);
parent.lost = 0;
}
private void _add_in_r_prime (Type1Node<G> node) {
#if DEBUG
_dump ("Start _add_in_r_prime: %p(%s)".printf (node, (string) node.data));
#endif
int degree = node.degree ();
Type1Node<G>? insertion_point = null;
if (degree < _a.length) {
insertion_point = _a[degree];
}
if (insertion_point == null) {
if (_r_prime.type1_children_tail != null) {
node.brothers_prev = _r_prime.type1_children_tail;
_r_prime.type1_children_tail.brothers_next = node;
} else {
_r_prime.type1_children_head = node;
}
_r_prime.type1_children_tail = node;
} else {
if (insertion_point.brothers_prev != null) {
insertion_point.brothers_prev.brothers_next = node;
node.brothers_prev = insertion_point.brothers_prev;
} else {
_r_prime.type1_children_head = node;
}
node.brothers_next = insertion_point;
insertion_point.brothers_prev = node;
}
node.parent = _r_prime;
// Maintain A, B and LP
if (degree >= _a.length) {
_a.resize (degree + 1);
_b.resize (degree + 1);
}
// If there is already a child of such degree
if (_a[degree] == null) {
_b[degree] = true;
} else {
// Else if there is an odd number of child of such degree
if (_b[degree]) {
// Make a pair
NodePair<G> pair = new NodePair<G> (node, node.brothers_next);
node.brothers_next.pair = pair;
node.pair = pair;
if (_lp_head == null) {
_lp_tail = pair;
_lp_head = (owned)pair;
} else {
pair.lp_prev = _lp_tail;
_lp_tail.lp_next = (owned)pair;
_lp_tail = _lp_tail.lp_next;
}
// There is now an even number of child of such degree
_b[degree] = false;
} else {
_b[degree] = true;
}
}
_a[degree] = node;
#if DEBUG
_dump ("End _add_in_r_prime: %p(%s)".printf (node, (string) node.data));
#endif
}
private void _remove_type1_node (Type1Node<G> node, bool with_iteration) {
#if DEBUG
_dump ("Start _remove_type1_node: %p(%s)".printf (node, (string) node.data));
#endif
if (node.parent == _r_prime) {
_updated_degree (node, false);
} else {
// Maintain LL
if (node.ll_prev != null) {
node.ll_prev.ll_next = node.ll_next;
} else if (_ll_head == node) {
_ll_head = node.ll_next;
}
if (node.ll_next != null) {
node.ll_next.ll_prev = node.ll_prev;
} else if (_ll_tail == node) {
_ll_tail = node.ll_prev;
}
if (node.parent != null) {
if (node.parent.parent == _r_prime) {
_updated_degree ((Type1Node<G>) node.parent, true);
} else if (node.parent.parent != null) {
Type1Node<G> parent = (Type1Node<G>) node.parent;
// Increment parent's lost count
parent.lost++;
// And add it to LL if needed
if (parent.lost > 1) {
if (_ll_tail != null) {
parent.ll_prev = _ll_tail;
_ll_tail.ll_next = parent;
} else {
_ll_head = parent;
}
_ll_tail = parent;
}
}
}
}
// Check whether removed node is P
if (node == _p) {
_p = _r;
}
// Maintain brothers list
node.remove ();
// Maintain iteration
if (with_iteration) {
if (node.iter_prev != null) {
node.iter_prev.iter_next = node.iter_next;
} else if (_iter_head == node) {
_iter_head = node.iter_next;
}
if (node.iter_next != null) {
node.iter_next.iter_prev = node.iter_prev;
} else if (_iter_tail == node) {
_iter_tail = node.iter_prev;
}
}
#if DEBUG
_dump ("End _remove_type1_node: %p(%s)".printf (node, (string) node.data));
#endif
}
private void _updated_degree (Type1Node<G> node, bool child_removed) {
int degree = node.degree ();
// Ensure proper sizes of A and B
if (degree >= _a.length) {
_a.resize (degree + 1);
_b.resize (degree + 1);
}
// Maintain A and B
if (child_removed && _a[degree - 1] == null) {
_a[degree - 1] = node;
_b[degree - 1] = ! _b[degree - 1];
}
_b[degree] = ! _b[degree];
if (_a[degree] == node) {
Type1Node<G> next = node.brothers_next;
if (next != null && next.degree () == degree) {
_a[degree] = next;
} else {
_a[degree] = null;
int i = _a.length - 1;
while (i >= 0 && _a[i] == null) {
i--;
}
_a.resize (i + 1);
_b.resize (i + 1);
}
}
// Maintain LP
if (node.pair != null) {
unowned NodePair<G> pair = node.pair;
Type1Node<G> other = (pair.node1 == node ? pair.node2 : pair.node1);
node.pair = null;
other.pair = null;
if (pair.lp_next != null) {
pair.lp_next.lp_prev = pair.lp_prev;
} else {
_lp_tail = pair.lp_prev;
}
if (pair.lp_prev != null) {
pair.lp_prev.lp_next = (owned)pair.lp_next;
} else {
_lp_head = (owned)pair.lp_next;
}
}
}
private void _remove_type2_node (Type2Node<G> node, bool with_iteration) {
#if DEBUG
_dump ("Start _remove_type2_node: %p(%s)".printf (node, (string) node.data));
#endif
((Type1Node<G>) node.parent).type2_child = null;
node.parent = null;
// For now we can't have type2 node other than R' (left for reference)
#if false
// Maintain LM
if (node != _r_prime) {
if (node.lm_prev != null) {
node.lm_prev.lm_next = node.lm_next;
} else if (_lm_head == node) {
_lm_head = node.lm_next;
}
if (node.lm_next != null) {
node.lm_next.lm_prev = node.lm_prev;
} else if (_lm_tail == node) {
_lm_tail = node.lm_prev;
}
node.lm_next = null;
node.lm_prev = null;
}
#endif
// Maintain iteration
if (with_iteration) {
if (node.iter_prev != null) {
node.iter_prev.iter_next = node.iter_next;
} else if (_iter_head == node) {
_iter_head = node.iter_next;
}
if (node.iter_next != null) {
node.iter_next.iter_prev = node.iter_prev;
} else if (_iter_tail == node) {
_iter_tail = node.iter_prev;
}
}
#if DEBUG
_dump ("End _remove_type2_node: %p(%s)".printf (node, (string) node.data));
#endif
}
#if DEBUG
public void _dump (string message) {
stdout.printf (">>>> %s\n", message);
stdout.printf ("A.length = %d:", _a.length);
foreach (Node<G>? node in _a) {
stdout.printf (" %p(%s);", node, node != null ? (string) node.data : null);
}
stdout.printf ("\n");
stdout.printf ("B.length = %d:", _b.length);
foreach (bool even in _b) {
stdout.printf (" %s;", even.to_string ());
}
stdout.printf ("\n");
stdout.printf ("LP:");
unowned NodePair<G>? pair = _lp_head;
while (pair != null) {
stdout.printf (" (%p(%s),%p(%s));", pair.node1, (string) pair.node1.data, pair.node2, (string) pair.node2.data);
pair = pair.lp_next;
}
stdout.printf ("\n");
stdout.printf ("LL:");
unowned Type1Node<G>? node = _ll_head;
while (node != null) {
stdout.printf (" %p(%s);", node, (string) node.data);
node = node.ll_next;
}
stdout.printf ("\n");
stdout.printf ("ITER:");
unowned Node<G>? inode_prev = null;
unowned Node<G>? inode = _iter_head;
while (inode != null) {
stdout.printf (" %p(%s);", inode, (string) inode.data);
assert (inode.iter_prev == inode_prev);
inode_prev = inode;
inode = inode.iter_next;
}
stdout.printf ("\n");
stdout.printf ("%s\n", _r != null ? _r.to_string () : null);
stdout.printf ("\n");
}
#endif
private abstract class Node<G> {
public G data;
public weak Node<G>? parent = null;
public int type1_children_count;
public Type1Node<G>? type1_children_head = null;
public Type1Node<G>? type1_children_tail = null;
public unowned Node<G>? iter_prev;
public unowned Node<G>? iter_next = null;
public bool pending_drop;
protected Node (G data, ref unowned Node<G>? head, ref unowned Node<G>? tail) {
this.data = data;
iter_prev = tail;
tail = this;
if (iter_prev != null) {
iter_prev.iter_next = this;
}
if (head == null) {
head = this;
}
}
public inline int degree () {
return type1_children_count;
}
#if DEBUG
public string children_to_string (int level = 0) {
StringBuilder builder = new StringBuilder ();
bool first = true;
Type1Node<G> child = type1_children_head;
while (child != null) {
if (!first) {
builder.append (",\n");
}
first = false;
builder.append (child.to_string (level));
child = child.brothers_next;
}
return builder.str;
}
public abstract string to_string (int level = 0);
#endif
}
private class Type1Node<G> : Node<G> {
public uint lost;
public weak Type1Node<G>? brothers_prev = null;
public Type1Node<G>? brothers_next = null;
public Type2Node<G>? type2_child = null;
public weak Type1Node<G>? ll_prev = null;
public Type1Node<G>? ll_next = null;
public weak NodePair<G>? pair = null;
public Type1Node (G data, ref unowned Node<G>? head, ref unowned Node<G>? tail) {
base (data, ref head, ref tail);
}
public inline void add (Type1Node<G> node) {
node.parent = this;
if (type1_children_head == null) {
type1_children_head = node;
} else {
node.brothers_prev = type1_children_tail;
}
if (type1_children_tail != null) {
type1_children_tail.brothers_next = node;
}
type1_children_tail = node;
type1_children_count++;
}
public inline void remove () {
if (brothers_prev == null) {
parent.type1_children_head = brothers_next;
} else {
brothers_prev.brothers_next = brothers_next;
}
if (brothers_next == null) {
parent.type1_children_tail = brothers_prev;
} else {
brothers_next.brothers_prev = brothers_prev;
}
parent.type1_children_count--;
parent = null;
brothers_prev = null;
brothers_next = null;
}
#if DEBUG
public override string to_string (int level = 0) {
StringBuilder builder = new StringBuilder ();
builder.append (string.nfill (level, '\t'));
builder.append ("(");
builder.append_printf("%p(%s)/%u", this, (string)data, lost);
if (type1_children_head != null || type2_child != null) {
builder.append (":\n");
}
if (type1_children_head != null) {
builder.append (children_to_string (level + 1));
}
if (type1_children_head != null && type2_child != null) {
builder.append (",\n");
}
if (type2_child != null) {
builder.append (type2_child.to_string (level + 1));
}
if (type1_children_head != null || type2_child != null) {
builder.append ("\n");
builder.append (string.nfill (level, '\t'));
}
builder.append (")");
return builder.str;
}
#endif
}
private class Type2Node<G> : Node<G> {
// For now we can't have type2 node other than R' (left for reference)
#if false
public weak Type2Node<G>? lm_prev = null;
public Type2Node<G>? lm_next = null;
#endif
public Type2Node (G data, ref unowned Node<G>? head, ref unowned Node<G>? tail) {
base (data, ref head, ref tail);
}
#if DEBUG
public override string to_string (int level = 0) {
StringBuilder builder = new StringBuilder ();
builder.append (string.nfill (level, '\t'));
builder.append_printf ("[%p(%s)", this, (string)data);
if (type1_children_head != null) {
builder.append (":\n");
builder.append (children_to_string (level + 1));
builder.append ("\n");
builder.append (string.nfill (level, '\t'));
}
builder.append ("]");
return builder.str;
}
#endif
}
private class DummyNode<G> : Node<G> {
public DummyNode (ref unowned Node<G>? prev_next, ref unowned Node<G>? next_prev, Node<G>? iter_prev, Node<G>? iter_next) {
#if DEBUG
base ("<<dummy>>", ref prev_next, ref next_prev);
#else
base (null, ref prev_next, ref next_prev);
#endif
this.iter_prev = iter_prev;
this.iter_next = iter_next;
prev_next = next_prev = this;
}
#if DEBUG
public override string to_string (int level = 0) {
StringBuilder builder = new StringBuilder ();
builder.append (string.nfill (level, '\t'));
builder.append ("%p<<dummy>>".printf(this));
return builder.str;
}
#endif
}
[Compact]
private class NodePair<G> {
public unowned NodePair<G>? lp_prev = null;
public NodePair<G>? lp_next = null;
public unowned Type1Node<G> node1 = null;
public unowned Type1Node<G> node2 = null;
public NodePair (Type1Node<G> node1, Type1Node<G> node2) {
this.node1 = node1;
this.node2 = node2;
}
}
private class Iterator<G> : Object, Traversable<G>, Gee.Iterator<G> {
public Iterator (PriorityQueue<G> queue) {
this.queue = queue;
this.position = null;
this.previous = null;
this.stamp = queue._stamp;
}
public Iterator.from_iterator (Iterator<G> iter) {
queue = iter.queue;
position = iter.position;
previous = iter.previous;
stamp = iter.stamp;
}
public bool next () {
unowned Node<G>? next = _get_next_node ();
if (next != null) {
previous = position;
position = next;
}
return next != null;
}
public bool has_next () {
return _get_next_node () != null;
}
private inline unowned Node<G>? _get_next_node () {
if (position != null) {
return position.iter_next;
} else {
return (previous != null) ? previous.iter_next : queue._iter_head;
}
}
public new G get () {
assert (stamp == queue._stamp);
assert (position != null);
return position.data;
}
public void remove () {
assert (stamp == queue._stamp);
assert (position != null);
DummyNode<G> dn;
if (previous != null) {
dn = new DummyNode<G> (ref previous.iter_next, ref position.iter_prev, previous, position);
} else {
dn = new DummyNode<G> (ref queue._iter_head, ref position.iter_prev, null, position);
}
queue._delete (position);
position = null;
if (previous != null) {
previous.iter_next = dn.iter_next;
}
if (dn == queue._iter_head) {
queue._iter_head = dn.iter_next;
}
if (dn.iter_next != null) {
dn.iter_next.iter_prev = previous;
}
if (dn == queue._iter_tail) {
queue._iter_tail = previous;
}
stamp++;
assert (stamp == queue._stamp);
}
public bool read_only { get { return false; } }
public bool valid { get { return position != null; } }
public bool foreach (ForallFunc<G> f) {
if (position == null) {
position = (previous != null) ? previous.iter_next : queue._iter_head;
}
if (position == null) {
return true;
}
if (!f (position.data)) {
return false;
}
while (position.iter_next != null) {
previous = position;
position = position.iter_next;
if (!f (position.data)) {
return false;
}
}
return true;
}
public Gee.Iterator<G>[] tee (uint forks) {
if (forks == 0) {
return new Gee.Iterator<G>[0];
} else {
Gee.Iterator<G>[] result = new Gee.Iterator<G>[forks];
result[0] = this;
for (uint i = 1; i < forks; i++) {
result[i] = new Iterator<G>.from_iterator (this);
}
return result;
}
}
protected PriorityQueue<G> queue;
protected unowned Node<G>? position;
protected unowned Node<G>? previous;
protected int stamp;
}
}