dust3d/thirdparty/QuadriFlow/3rd/lemon-1.3.1/lemon/planarity.h

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C++
Executable File

/* -*- mode: C++; indent-tabs-mode: nil; -*-
*
* This file is a part of LEMON, a generic C++ optimization library.
*
* Copyright (C) 2003-2013
* Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
* (Egervary Research Group on Combinatorial Optimization, EGRES).
*
* Permission to use, modify and distribute this software is granted
* provided that this copyright notice appears in all copies. For
* precise terms see the accompanying LICENSE file.
*
* This software is provided "AS IS" with no warranty of any kind,
* express or implied, and with no claim as to its suitability for any
* purpose.
*
*/
#ifndef LEMON_PLANARITY_H
#define LEMON_PLANARITY_H
/// \ingroup planar
/// \file
/// \brief Planarity checking, embedding, drawing and coloring
#include <vector>
#include <list>
#include <lemon/dfs.h>
#include <lemon/bfs.h>
#include <lemon/radix_sort.h>
#include <lemon/maps.h>
#include <lemon/path.h>
#include <lemon/bucket_heap.h>
#include <lemon/adaptors.h>
#include <lemon/edge_set.h>
#include <lemon/color.h>
#include <lemon/dim2.h>
namespace lemon {
namespace _planarity_bits {
template <typename Graph>
struct PlanarityVisitor : DfsVisitor<Graph> {
TEMPLATE_GRAPH_TYPEDEFS(Graph);
typedef typename Graph::template NodeMap<Arc> PredMap;
typedef typename Graph::template EdgeMap<bool> TreeMap;
typedef typename Graph::template NodeMap<int> OrderMap;
typedef std::vector<Node> OrderList;
typedef typename Graph::template NodeMap<int> LowMap;
typedef typename Graph::template NodeMap<int> AncestorMap;
PlanarityVisitor(const Graph& graph,
PredMap& pred_map, TreeMap& tree_map,
OrderMap& order_map, OrderList& order_list,
AncestorMap& ancestor_map, LowMap& low_map)
: _graph(graph), _pred_map(pred_map), _tree_map(tree_map),
_order_map(order_map), _order_list(order_list),
_ancestor_map(ancestor_map), _low_map(low_map) {}
void reach(const Node& node) {
_order_map[node] = _order_list.size();
_low_map[node] = _order_list.size();
_ancestor_map[node] = _order_list.size();
_order_list.push_back(node);
}
void discover(const Arc& arc) {
Node target = _graph.target(arc);
_tree_map[arc] = true;
_pred_map[target] = arc;
}
void examine(const Arc& arc) {
Node source = _graph.source(arc);
Node target = _graph.target(arc);
if (_order_map[target] < _order_map[source] && !_tree_map[arc]) {
if (_low_map[source] > _order_map[target]) {
_low_map[source] = _order_map[target];
}
if (_ancestor_map[source] > _order_map[target]) {
_ancestor_map[source] = _order_map[target];
}
}
}
void backtrack(const Arc& arc) {
Node source = _graph.source(arc);
Node target = _graph.target(arc);
if (_low_map[source] > _low_map[target]) {
_low_map[source] = _low_map[target];
}
}
const Graph& _graph;
PredMap& _pred_map;
TreeMap& _tree_map;
OrderMap& _order_map;
OrderList& _order_list;
AncestorMap& _ancestor_map;
LowMap& _low_map;
};
template <typename Graph, bool embedding = true>
struct NodeDataNode {
int prev, next;
int visited;
typename Graph::Arc first;
bool inverted;
};
template <typename Graph>
struct NodeDataNode<Graph, false> {
int prev, next;
int visited;
};
template <typename Graph>
struct ChildListNode {
typedef typename Graph::Node Node;
Node first;
Node prev, next;
};
template <typename Graph>
struct ArcListNode {
typename Graph::Arc prev, next;
};
template <typename Graph>
class PlanarityChecking {
private:
TEMPLATE_GRAPH_TYPEDEFS(Graph);
const Graph& _graph;
private:
typedef typename Graph::template NodeMap<Arc> PredMap;
typedef typename Graph::template EdgeMap<bool> TreeMap;
typedef typename Graph::template NodeMap<int> OrderMap;
typedef std::vector<Node> OrderList;
typedef typename Graph::template NodeMap<int> LowMap;
typedef typename Graph::template NodeMap<int> AncestorMap;
typedef _planarity_bits::NodeDataNode<Graph> NodeDataNode;
typedef std::vector<NodeDataNode> NodeData;
typedef _planarity_bits::ChildListNode<Graph> ChildListNode;
typedef typename Graph::template NodeMap<ChildListNode> ChildLists;
typedef typename Graph::template NodeMap<std::list<int> > MergeRoots;
typedef typename Graph::template NodeMap<bool> EmbedArc;
public:
PlanarityChecking(const Graph& graph) : _graph(graph) {}
bool run() {
typedef _planarity_bits::PlanarityVisitor<Graph> Visitor;
PredMap pred_map(_graph, INVALID);
TreeMap tree_map(_graph, false);
OrderMap order_map(_graph, -1);
OrderList order_list;
AncestorMap ancestor_map(_graph, -1);
LowMap low_map(_graph, -1);
Visitor visitor(_graph, pred_map, tree_map,
order_map, order_list, ancestor_map, low_map);
DfsVisit<Graph, Visitor> visit(_graph, visitor);
visit.run();
ChildLists child_lists(_graph);
createChildLists(tree_map, order_map, low_map, child_lists);
NodeData node_data(2 * order_list.size());
EmbedArc embed_arc(_graph, false);
MergeRoots merge_roots(_graph);
for (int i = order_list.size() - 1; i >= 0; --i) {
Node node = order_list[i];
Node source = node;
for (OutArcIt e(_graph, node); e != INVALID; ++e) {
Node target = _graph.target(e);
if (order_map[source] < order_map[target] && tree_map[e]) {
initFace(target, node_data, order_map, order_list);
}
}
for (OutArcIt e(_graph, node); e != INVALID; ++e) {
Node target = _graph.target(e);
if (order_map[source] < order_map[target] && !tree_map[e]) {
embed_arc[target] = true;
walkUp(target, source, i, pred_map, low_map,
order_map, order_list, node_data, merge_roots);
}
}
for (typename MergeRoots::Value::iterator it =
merge_roots[node].begin();
it != merge_roots[node].end(); ++it) {
int rn = *it;
walkDown(rn, i, node_data, order_list, child_lists,
ancestor_map, low_map, embed_arc, merge_roots);
}
merge_roots[node].clear();
for (OutArcIt e(_graph, node); e != INVALID; ++e) {
Node target = _graph.target(e);
if (order_map[source] < order_map[target] && !tree_map[e]) {
if (embed_arc[target]) {
return false;
}
}
}
}
return true;
}
private:
void createChildLists(const TreeMap& tree_map, const OrderMap& order_map,
const LowMap& low_map, ChildLists& child_lists) {
for (NodeIt n(_graph); n != INVALID; ++n) {
Node source = n;
std::vector<Node> targets;
for (OutArcIt e(_graph, n); e != INVALID; ++e) {
Node target = _graph.target(e);
if (order_map[source] < order_map[target] && tree_map[e]) {
targets.push_back(target);
}
}
if (targets.size() == 0) {
child_lists[source].first = INVALID;
} else if (targets.size() == 1) {
child_lists[source].first = targets[0];
child_lists[targets[0]].prev = INVALID;
child_lists[targets[0]].next = INVALID;
} else {
radixSort(targets.begin(), targets.end(), mapToFunctor(low_map));
for (int i = 1; i < int(targets.size()); ++i) {
child_lists[targets[i]].prev = targets[i - 1];
child_lists[targets[i - 1]].next = targets[i];
}
child_lists[targets.back()].next = INVALID;
child_lists[targets.front()].prev = INVALID;
child_lists[source].first = targets.front();
}
}
}
void walkUp(const Node& node, Node root, int rorder,
const PredMap& pred_map, const LowMap& low_map,
const OrderMap& order_map, const OrderList& order_list,
NodeData& node_data, MergeRoots& merge_roots) {
int na, nb;
bool da, db;
na = nb = order_map[node];
da = true; db = false;
while (true) {
if (node_data[na].visited == rorder) break;
if (node_data[nb].visited == rorder) break;
node_data[na].visited = rorder;
node_data[nb].visited = rorder;
int rn = -1;
if (na >= int(order_list.size())) {
rn = na;
} else if (nb >= int(order_list.size())) {
rn = nb;
}
if (rn == -1) {
int nn;
nn = da ? node_data[na].prev : node_data[na].next;
da = node_data[nn].prev != na;
na = nn;
nn = db ? node_data[nb].prev : node_data[nb].next;
db = node_data[nn].prev != nb;
nb = nn;
} else {
Node rep = order_list[rn - order_list.size()];
Node parent = _graph.source(pred_map[rep]);
if (low_map[rep] < rorder) {
merge_roots[parent].push_back(rn);
} else {
merge_roots[parent].push_front(rn);
}
if (parent != root) {
na = nb = order_map[parent];
da = true; db = false;
} else {
break;
}
}
}
}
void walkDown(int rn, int rorder, NodeData& node_data,
OrderList& order_list, ChildLists& child_lists,
AncestorMap& ancestor_map, LowMap& low_map,
EmbedArc& embed_arc, MergeRoots& merge_roots) {
std::vector<std::pair<int, bool> > merge_stack;
for (int di = 0; di < 2; ++di) {
bool rd = di == 0;
int pn = rn;
int n = rd ? node_data[rn].next : node_data[rn].prev;
while (n != rn) {
Node node = order_list[n];
if (embed_arc[node]) {
// Merging components on the critical path
while (!merge_stack.empty()) {
// Component root
int cn = merge_stack.back().first;
bool cd = merge_stack.back().second;
merge_stack.pop_back();
// Parent of component
int dn = merge_stack.back().first;
bool dd = merge_stack.back().second;
merge_stack.pop_back();
Node parent = order_list[dn];
// Erasing from merge_roots
merge_roots[parent].pop_front();
Node child = order_list[cn - order_list.size()];
// Erasing from child_lists
if (child_lists[child].prev != INVALID) {
child_lists[child_lists[child].prev].next =
child_lists[child].next;
} else {
child_lists[parent].first = child_lists[child].next;
}
if (child_lists[child].next != INVALID) {
child_lists[child_lists[child].next].prev =
child_lists[child].prev;
}
// Merging external faces
{
int en = cn;
cn = cd ? node_data[cn].prev : node_data[cn].next;
cd = node_data[cn].next == en;
}
if (cd) node_data[cn].next = dn; else node_data[cn].prev = dn;
if (dd) node_data[dn].prev = cn; else node_data[dn].next = cn;
}
bool d = pn == node_data[n].prev;
if (node_data[n].prev == node_data[n].next &&
node_data[n].inverted) {
d = !d;
}
// Embedding arc into external face
if (rd) node_data[rn].next = n; else node_data[rn].prev = n;
if (d) node_data[n].prev = rn; else node_data[n].next = rn;
pn = rn;
embed_arc[order_list[n]] = false;
}
if (!merge_roots[node].empty()) {
bool d = pn == node_data[n].prev;
merge_stack.push_back(std::make_pair(n, d));
int rn = merge_roots[node].front();
int xn = node_data[rn].next;
Node xnode = order_list[xn];
int yn = node_data[rn].prev;
Node ynode = order_list[yn];
bool rd;
if (!external(xnode, rorder, child_lists,
ancestor_map, low_map)) {
rd = true;
} else if (!external(ynode, rorder, child_lists,
ancestor_map, low_map)) {
rd = false;
} else if (pertinent(xnode, embed_arc, merge_roots)) {
rd = true;
} else {
rd = false;
}
merge_stack.push_back(std::make_pair(rn, rd));
pn = rn;
n = rd ? xn : yn;
} else if (!external(node, rorder, child_lists,
ancestor_map, low_map)) {
int nn = (node_data[n].next != pn ?
node_data[n].next : node_data[n].prev);
bool nd = n == node_data[nn].prev;
if (nd) node_data[nn].prev = pn;
else node_data[nn].next = pn;
if (n == node_data[pn].prev) node_data[pn].prev = nn;
else node_data[pn].next = nn;
node_data[nn].inverted =
(node_data[nn].prev == node_data[nn].next && nd != rd);
n = nn;
}
else break;
}
if (!merge_stack.empty() || n == rn) {
break;
}
}
}
void initFace(const Node& node, NodeData& node_data,
const OrderMap& order_map, const OrderList& order_list) {
int n = order_map[node];
int rn = n + order_list.size();
node_data[n].next = node_data[n].prev = rn;
node_data[rn].next = node_data[rn].prev = n;
node_data[n].visited = order_list.size();
node_data[rn].visited = order_list.size();
}
bool external(const Node& node, int rorder,
ChildLists& child_lists, AncestorMap& ancestor_map,
LowMap& low_map) {
Node child = child_lists[node].first;
if (child != INVALID) {
if (low_map[child] < rorder) return true;
}
if (ancestor_map[node] < rorder) return true;
return false;
}
bool pertinent(const Node& node, const EmbedArc& embed_arc,
const MergeRoots& merge_roots) {
return !merge_roots[node].empty() || embed_arc[node];
}
};
}
/// \ingroup planar
///
/// \brief Planarity checking of an undirected simple graph
///
/// This function implements the Boyer-Myrvold algorithm for
/// planarity checking of an undirected simple graph. It is a simplified
/// version of the PlanarEmbedding algorithm class because neither
/// the embedding nor the Kuratowski subdivisons are computed.
template <typename GR>
bool checkPlanarity(const GR& graph) {
_planarity_bits::PlanarityChecking<GR> pc(graph);
return pc.run();
}
/// \ingroup planar
///
/// \brief Planar embedding of an undirected simple graph
///
/// This class implements the Boyer-Myrvold algorithm for planar
/// embedding of an undirected simple graph. The planar embedding is an
/// ordering of the outgoing edges of the nodes, which is a possible
/// configuration to draw the graph in the plane. If there is not
/// such ordering then the graph contains a K<sub>5</sub> (full graph
/// with 5 nodes) or a K<sub>3,3</sub> (complete bipartite graph on
/// 3 Red and 3 Blue nodes) subdivision.
///
/// The current implementation calculates either an embedding or a
/// Kuratowski subdivision. The running time of the algorithm is O(n).
///
/// \see PlanarDrawing, checkPlanarity()
template <typename Graph>
class PlanarEmbedding {
private:
TEMPLATE_GRAPH_TYPEDEFS(Graph);
const Graph& _graph;
typename Graph::template ArcMap<Arc> _embedding;
typename Graph::template EdgeMap<bool> _kuratowski;
private:
typedef typename Graph::template NodeMap<Arc> PredMap;
typedef typename Graph::template EdgeMap<bool> TreeMap;
typedef typename Graph::template NodeMap<int> OrderMap;
typedef std::vector<Node> OrderList;
typedef typename Graph::template NodeMap<int> LowMap;
typedef typename Graph::template NodeMap<int> AncestorMap;
typedef _planarity_bits::NodeDataNode<Graph> NodeDataNode;
typedef std::vector<NodeDataNode> NodeData;
typedef _planarity_bits::ChildListNode<Graph> ChildListNode;
typedef typename Graph::template NodeMap<ChildListNode> ChildLists;
typedef typename Graph::template NodeMap<std::list<int> > MergeRoots;
typedef typename Graph::template NodeMap<Arc> EmbedArc;
typedef _planarity_bits::ArcListNode<Graph> ArcListNode;
typedef typename Graph::template ArcMap<ArcListNode> ArcLists;
typedef typename Graph::template NodeMap<bool> FlipMap;
typedef typename Graph::template NodeMap<int> TypeMap;
enum IsolatorNodeType {
HIGHX = 6, LOWX = 7,
HIGHY = 8, LOWY = 9,
ROOT = 10, PERTINENT = 11,
INTERNAL = 12
};
public:
/// \brief The map type for storing the embedding
///
/// The map type for storing the embedding.
/// \see embeddingMap()
typedef typename Graph::template ArcMap<Arc> EmbeddingMap;
/// \brief Constructor
///
/// Constructor.
/// \pre The graph must be simple, i.e. it should not
/// contain parallel or loop arcs.
PlanarEmbedding(const Graph& graph)
: _graph(graph), _embedding(_graph), _kuratowski(graph, false) {}
/// \brief Run the algorithm.
///
/// This function runs the algorithm.
/// \param kuratowski If this parameter is set to \c false, then the
/// algorithm does not compute a Kuratowski subdivision.
/// \return \c true if the graph is planar.
bool run(bool kuratowski = true) {
typedef _planarity_bits::PlanarityVisitor<Graph> Visitor;
PredMap pred_map(_graph, INVALID);
TreeMap tree_map(_graph, false);
OrderMap order_map(_graph, -1);
OrderList order_list;
AncestorMap ancestor_map(_graph, -1);
LowMap low_map(_graph, -1);
Visitor visitor(_graph, pred_map, tree_map,
order_map, order_list, ancestor_map, low_map);
DfsVisit<Graph, Visitor> visit(_graph, visitor);
visit.run();
ChildLists child_lists(_graph);
createChildLists(tree_map, order_map, low_map, child_lists);
NodeData node_data(2 * order_list.size());
EmbedArc embed_arc(_graph, INVALID);
MergeRoots merge_roots(_graph);
ArcLists arc_lists(_graph);
FlipMap flip_map(_graph, false);
for (int i = order_list.size() - 1; i >= 0; --i) {
Node node = order_list[i];
node_data[i].first = INVALID;
Node source = node;
for (OutArcIt e(_graph, node); e != INVALID; ++e) {
Node target = _graph.target(e);
if (order_map[source] < order_map[target] && tree_map[e]) {
initFace(target, arc_lists, node_data,
pred_map, order_map, order_list);
}
}
for (OutArcIt e(_graph, node); e != INVALID; ++e) {
Node target = _graph.target(e);
if (order_map[source] < order_map[target] && !tree_map[e]) {
embed_arc[target] = e;
walkUp(target, source, i, pred_map, low_map,
order_map, order_list, node_data, merge_roots);
}
}
for (typename MergeRoots::Value::iterator it =
merge_roots[node].begin(); it != merge_roots[node].end(); ++it) {
int rn = *it;
walkDown(rn, i, node_data, arc_lists, flip_map, order_list,
child_lists, ancestor_map, low_map, embed_arc, merge_roots);
}
merge_roots[node].clear();
for (OutArcIt e(_graph, node); e != INVALID; ++e) {
Node target = _graph.target(e);
if (order_map[source] < order_map[target] && !tree_map[e]) {
if (embed_arc[target] != INVALID) {
if (kuratowski) {
isolateKuratowski(e, node_data, arc_lists, flip_map,
order_map, order_list, pred_map, child_lists,
ancestor_map, low_map,
embed_arc, merge_roots);
}
return false;
}
}
}
}
for (int i = 0; i < int(order_list.size()); ++i) {
mergeRemainingFaces(order_list[i], node_data, order_list, order_map,
child_lists, arc_lists);
storeEmbedding(order_list[i], node_data, order_map, pred_map,
arc_lists, flip_map);
}
return true;
}
/// \brief Give back the successor of an arc
///
/// This function gives back the successor of an arc. It makes
/// possible to query the cyclic order of the outgoing arcs from
/// a node.
Arc next(const Arc& arc) const {
return _embedding[arc];
}
/// \brief Give back the calculated embedding map
///
/// This function gives back the calculated embedding map, which
/// contains the successor of each arc in the cyclic order of the
/// outgoing arcs of its source node.
const EmbeddingMap& embeddingMap() const {
return _embedding;
}
/// \brief Give back \c true if the given edge is in the Kuratowski
/// subdivision
///
/// This function gives back \c true if the given edge is in the found
/// Kuratowski subdivision.
/// \pre The \c run() function must be called with \c true parameter
/// before using this function.
bool kuratowski(const Edge& edge) const {
return _kuratowski[edge];
}
private:
void createChildLists(const TreeMap& tree_map, const OrderMap& order_map,
const LowMap& low_map, ChildLists& child_lists) {
for (NodeIt n(_graph); n != INVALID; ++n) {
Node source = n;
std::vector<Node> targets;
for (OutArcIt e(_graph, n); e != INVALID; ++e) {
Node target = _graph.target(e);
if (order_map[source] < order_map[target] && tree_map[e]) {
targets.push_back(target);
}
}
if (targets.size() == 0) {
child_lists[source].first = INVALID;
} else if (targets.size() == 1) {
child_lists[source].first = targets[0];
child_lists[targets[0]].prev = INVALID;
child_lists[targets[0]].next = INVALID;
} else {
radixSort(targets.begin(), targets.end(), mapToFunctor(low_map));
for (int i = 1; i < int(targets.size()); ++i) {
child_lists[targets[i]].prev = targets[i - 1];
child_lists[targets[i - 1]].next = targets[i];
}
child_lists[targets.back()].next = INVALID;
child_lists[targets.front()].prev = INVALID;
child_lists[source].first = targets.front();
}
}
}
void walkUp(const Node& node, Node root, int rorder,
const PredMap& pred_map, const LowMap& low_map,
const OrderMap& order_map, const OrderList& order_list,
NodeData& node_data, MergeRoots& merge_roots) {
int na, nb;
bool da, db;
na = nb = order_map[node];
da = true; db = false;
while (true) {
if (node_data[na].visited == rorder) break;
if (node_data[nb].visited == rorder) break;
node_data[na].visited = rorder;
node_data[nb].visited = rorder;
int rn = -1;
if (na >= int(order_list.size())) {
rn = na;
} else if (nb >= int(order_list.size())) {
rn = nb;
}
if (rn == -1) {
int nn;
nn = da ? node_data[na].prev : node_data[na].next;
da = node_data[nn].prev != na;
na = nn;
nn = db ? node_data[nb].prev : node_data[nb].next;
db = node_data[nn].prev != nb;
nb = nn;
} else {
Node rep = order_list[rn - order_list.size()];
Node parent = _graph.source(pred_map[rep]);
if (low_map[rep] < rorder) {
merge_roots[parent].push_back(rn);
} else {
merge_roots[parent].push_front(rn);
}
if (parent != root) {
na = nb = order_map[parent];
da = true; db = false;
} else {
break;
}
}
}
}
void walkDown(int rn, int rorder, NodeData& node_data,
ArcLists& arc_lists, FlipMap& flip_map,
OrderList& order_list, ChildLists& child_lists,
AncestorMap& ancestor_map, LowMap& low_map,
EmbedArc& embed_arc, MergeRoots& merge_roots) {
std::vector<std::pair<int, bool> > merge_stack;
for (int di = 0; di < 2; ++di) {
bool rd = di == 0;
int pn = rn;
int n = rd ? node_data[rn].next : node_data[rn].prev;
while (n != rn) {
Node node = order_list[n];
if (embed_arc[node] != INVALID) {
// Merging components on the critical path
while (!merge_stack.empty()) {
// Component root
int cn = merge_stack.back().first;
bool cd = merge_stack.back().second;
merge_stack.pop_back();
// Parent of component
int dn = merge_stack.back().first;
bool dd = merge_stack.back().second;
merge_stack.pop_back();
Node parent = order_list[dn];
// Erasing from merge_roots
merge_roots[parent].pop_front();
Node child = order_list[cn - order_list.size()];
// Erasing from child_lists
if (child_lists[child].prev != INVALID) {
child_lists[child_lists[child].prev].next =
child_lists[child].next;
} else {
child_lists[parent].first = child_lists[child].next;
}
if (child_lists[child].next != INVALID) {
child_lists[child_lists[child].next].prev =
child_lists[child].prev;
}
// Merging arcs + flipping
Arc de = node_data[dn].first;
Arc ce = node_data[cn].first;
flip_map[order_list[cn - order_list.size()]] = cd != dd;
if (cd != dd) {
std::swap(arc_lists[ce].prev, arc_lists[ce].next);
ce = arc_lists[ce].prev;
std::swap(arc_lists[ce].prev, arc_lists[ce].next);
}
{
Arc dne = arc_lists[de].next;
Arc cne = arc_lists[ce].next;
arc_lists[de].next = cne;
arc_lists[ce].next = dne;
arc_lists[dne].prev = ce;
arc_lists[cne].prev = de;
}
if (dd) {
node_data[dn].first = ce;
}
// Merging external faces
{
int en = cn;
cn = cd ? node_data[cn].prev : node_data[cn].next;
cd = node_data[cn].next == en;
if (node_data[cn].prev == node_data[cn].next &&
node_data[cn].inverted) {
cd = !cd;
}
}
if (cd) node_data[cn].next = dn; else node_data[cn].prev = dn;
if (dd) node_data[dn].prev = cn; else node_data[dn].next = cn;
}
bool d = pn == node_data[n].prev;
if (node_data[n].prev == node_data[n].next &&
node_data[n].inverted) {
d = !d;
}
// Add new arc
{
Arc arc = embed_arc[node];
Arc re = node_data[rn].first;
arc_lists[arc_lists[re].next].prev = arc;
arc_lists[arc].next = arc_lists[re].next;
arc_lists[arc].prev = re;
arc_lists[re].next = arc;
if (!rd) {
node_data[rn].first = arc;
}
Arc rev = _graph.oppositeArc(arc);
Arc e = node_data[n].first;
arc_lists[arc_lists[e].next].prev = rev;
arc_lists[rev].next = arc_lists[e].next;
arc_lists[rev].prev = e;
arc_lists[e].next = rev;
if (d) {
node_data[n].first = rev;
}
}
// Embedding arc into external face
if (rd) node_data[rn].next = n; else node_data[rn].prev = n;
if (d) node_data[n].prev = rn; else node_data[n].next = rn;
pn = rn;
embed_arc[order_list[n]] = INVALID;
}
if (!merge_roots[node].empty()) {
bool d = pn == node_data[n].prev;
if (node_data[n].prev == node_data[n].next &&
node_data[n].inverted) {
d = !d;
}
merge_stack.push_back(std::make_pair(n, d));
int rn = merge_roots[node].front();
int xn = node_data[rn].next;
Node xnode = order_list[xn];
int yn = node_data[rn].prev;
Node ynode = order_list[yn];
bool rd;
if (!external(xnode, rorder, child_lists, ancestor_map, low_map)) {
rd = true;
} else if (!external(ynode, rorder, child_lists,
ancestor_map, low_map)) {
rd = false;
} else if (pertinent(xnode, embed_arc, merge_roots)) {
rd = true;
} else {
rd = false;
}
merge_stack.push_back(std::make_pair(rn, rd));
pn = rn;
n = rd ? xn : yn;
} else if (!external(node, rorder, child_lists,
ancestor_map, low_map)) {
int nn = (node_data[n].next != pn ?
node_data[n].next : node_data[n].prev);
bool nd = n == node_data[nn].prev;
if (nd) node_data[nn].prev = pn;
else node_data[nn].next = pn;
if (n == node_data[pn].prev) node_data[pn].prev = nn;
else node_data[pn].next = nn;
node_data[nn].inverted =
(node_data[nn].prev == node_data[nn].next && nd != rd);
n = nn;
}
else break;
}
if (!merge_stack.empty() || n == rn) {
break;
}
}
}
void initFace(const Node& node, ArcLists& arc_lists,
NodeData& node_data, const PredMap& pred_map,
const OrderMap& order_map, const OrderList& order_list) {
int n = order_map[node];
int rn = n + order_list.size();
node_data[n].next = node_data[n].prev = rn;
node_data[rn].next = node_data[rn].prev = n;
node_data[n].visited = order_list.size();
node_data[rn].visited = order_list.size();
node_data[n].inverted = false;
node_data[rn].inverted = false;
Arc arc = pred_map[node];
Arc rev = _graph.oppositeArc(arc);
node_data[rn].first = arc;
node_data[n].first = rev;
arc_lists[arc].prev = arc;
arc_lists[arc].next = arc;
arc_lists[rev].prev = rev;
arc_lists[rev].next = rev;
}
void mergeRemainingFaces(const Node& node, NodeData& node_data,
OrderList& order_list, OrderMap& order_map,
ChildLists& child_lists, ArcLists& arc_lists) {
while (child_lists[node].first != INVALID) {
int dd = order_map[node];
Node child = child_lists[node].first;
int cd = order_map[child] + order_list.size();
child_lists[node].first = child_lists[child].next;
Arc de = node_data[dd].first;
Arc ce = node_data[cd].first;
if (de != INVALID) {
Arc dne = arc_lists[de].next;
Arc cne = arc_lists[ce].next;
arc_lists[de].next = cne;
arc_lists[ce].next = dne;
arc_lists[dne].prev = ce;
arc_lists[cne].prev = de;
}
node_data[dd].first = ce;
}
}
void storeEmbedding(const Node& node, NodeData& node_data,
OrderMap& order_map, PredMap& pred_map,
ArcLists& arc_lists, FlipMap& flip_map) {
if (node_data[order_map[node]].first == INVALID) return;
if (pred_map[node] != INVALID) {
Node source = _graph.source(pred_map[node]);
flip_map[node] = flip_map[node] != flip_map[source];
}
Arc first = node_data[order_map[node]].first;
Arc prev = first;
Arc arc = flip_map[node] ?
arc_lists[prev].prev : arc_lists[prev].next;
_embedding[prev] = arc;
while (arc != first) {
Arc next = arc_lists[arc].prev == prev ?
arc_lists[arc].next : arc_lists[arc].prev;
prev = arc; arc = next;
_embedding[prev] = arc;
}
}
bool external(const Node& node, int rorder,
ChildLists& child_lists, AncestorMap& ancestor_map,
LowMap& low_map) {
Node child = child_lists[node].first;
if (child != INVALID) {
if (low_map[child] < rorder) return true;
}
if (ancestor_map[node] < rorder) return true;
return false;
}
bool pertinent(const Node& node, const EmbedArc& embed_arc,
const MergeRoots& merge_roots) {
return !merge_roots[node].empty() || embed_arc[node] != INVALID;
}
int lowPoint(const Node& node, OrderMap& order_map, ChildLists& child_lists,
AncestorMap& ancestor_map, LowMap& low_map) {
int low_point;
Node child = child_lists[node].first;
if (child != INVALID) {
low_point = low_map[child];
} else {
low_point = order_map[node];
}
if (low_point > ancestor_map[node]) {
low_point = ancestor_map[node];
}
return low_point;
}
int findComponentRoot(Node root, Node node, ChildLists& child_lists,
OrderMap& order_map, OrderList& order_list) {
int order = order_map[root];
int norder = order_map[node];
Node child = child_lists[root].first;
while (child != INVALID) {
int corder = order_map[child];
if (corder > order && corder < norder) {
order = corder;
}
child = child_lists[child].next;
}
return order + order_list.size();
}
Node findPertinent(Node node, OrderMap& order_map, NodeData& node_data,
EmbedArc& embed_arc, MergeRoots& merge_roots) {
Node wnode =_graph.target(node_data[order_map[node]].first);
while (!pertinent(wnode, embed_arc, merge_roots)) {
wnode = _graph.target(node_data[order_map[wnode]].first);
}
return wnode;
}
Node findExternal(Node node, int rorder, OrderMap& order_map,
ChildLists& child_lists, AncestorMap& ancestor_map,
LowMap& low_map, NodeData& node_data) {
Node wnode =_graph.target(node_data[order_map[node]].first);
while (!external(wnode, rorder, child_lists, ancestor_map, low_map)) {
wnode = _graph.target(node_data[order_map[wnode]].first);
}
return wnode;
}
void markCommonPath(Node node, int rorder, Node& wnode, Node& znode,
OrderList& order_list, OrderMap& order_map,
NodeData& node_data, ArcLists& arc_lists,
EmbedArc& embed_arc, MergeRoots& merge_roots,
ChildLists& child_lists, AncestorMap& ancestor_map,
LowMap& low_map) {
Node cnode = node;
Node pred = INVALID;
while (true) {
bool pert = pertinent(cnode, embed_arc, merge_roots);
bool ext = external(cnode, rorder, child_lists, ancestor_map, low_map);
if (pert && ext) {
if (!merge_roots[cnode].empty()) {
int cn = merge_roots[cnode].back();
if (low_map[order_list[cn - order_list.size()]] < rorder) {
Arc arc = node_data[cn].first;
_kuratowski.set(arc, true);
pred = cnode;
cnode = _graph.target(arc);
continue;
}
}
wnode = znode = cnode;
return;
} else if (pert) {
wnode = cnode;
while (!external(cnode, rorder, child_lists, ancestor_map, low_map)) {
Arc arc = node_data[order_map[cnode]].first;
if (_graph.target(arc) == pred) {
arc = arc_lists[arc].next;
}
_kuratowski.set(arc, true);
Node next = _graph.target(arc);
pred = cnode; cnode = next;
}
znode = cnode;
return;
} else if (ext) {
znode = cnode;
while (!pertinent(cnode, embed_arc, merge_roots)) {
Arc arc = node_data[order_map[cnode]].first;
if (_graph.target(arc) == pred) {
arc = arc_lists[arc].next;
}
_kuratowski.set(arc, true);
Node next = _graph.target(arc);
pred = cnode; cnode = next;
}
wnode = cnode;
return;
} else {
Arc arc = node_data[order_map[cnode]].first;
if (_graph.target(arc) == pred) {
arc = arc_lists[arc].next;
}
_kuratowski.set(arc, true);
Node next = _graph.target(arc);
pred = cnode; cnode = next;
}
}
}
void orientComponent(Node root, int rn, OrderMap& order_map,
PredMap& pred_map, NodeData& node_data,
ArcLists& arc_lists, FlipMap& flip_map,
TypeMap& type_map) {
node_data[order_map[root]].first = node_data[rn].first;
type_map[root] = 1;
std::vector<Node> st, qu;
st.push_back(root);
while (!st.empty()) {
Node node = st.back();
st.pop_back();
qu.push_back(node);
Arc arc = node_data[order_map[node]].first;
if (type_map[_graph.target(arc)] == 0) {
st.push_back(_graph.target(arc));
type_map[_graph.target(arc)] = 1;
}
Arc last = arc, pred = arc;
arc = arc_lists[arc].next;
while (arc != last) {
if (type_map[_graph.target(arc)] == 0) {
st.push_back(_graph.target(arc));
type_map[_graph.target(arc)] = 1;
}
Arc next = arc_lists[arc].next != pred ?
arc_lists[arc].next : arc_lists[arc].prev;
pred = arc; arc = next;
}
}
type_map[root] = 2;
flip_map[root] = false;
for (int i = 1; i < int(qu.size()); ++i) {
Node node = qu[i];
while (type_map[node] != 2) {
st.push_back(node);
type_map[node] = 2;
node = _graph.source(pred_map[node]);
}
bool flip = flip_map[node];
while (!st.empty()) {
node = st.back();
st.pop_back();
flip_map[node] = flip != flip_map[node];
flip = flip_map[node];
if (flip) {
Arc arc = node_data[order_map[node]].first;
std::swap(arc_lists[arc].prev, arc_lists[arc].next);
arc = arc_lists[arc].prev;
std::swap(arc_lists[arc].prev, arc_lists[arc].next);
node_data[order_map[node]].first = arc;
}
}
}
for (int i = 0; i < int(qu.size()); ++i) {
Arc arc = node_data[order_map[qu[i]]].first;
Arc last = arc, pred = arc;
arc = arc_lists[arc].next;
while (arc != last) {
if (arc_lists[arc].next == pred) {
std::swap(arc_lists[arc].next, arc_lists[arc].prev);
}
pred = arc; arc = arc_lists[arc].next;
}
}
}
void setFaceFlags(Node root, Node wnode, Node ynode, Node xnode,
OrderMap& order_map, NodeData& node_data,
TypeMap& type_map) {
Node node = _graph.target(node_data[order_map[root]].first);
while (node != ynode) {
type_map[node] = HIGHY;
node = _graph.target(node_data[order_map[node]].first);
}
while (node != wnode) {
type_map[node] = LOWY;
node = _graph.target(node_data[order_map[node]].first);
}
node = _graph.target(node_data[order_map[wnode]].first);
while (node != xnode) {
type_map[node] = LOWX;
node = _graph.target(node_data[order_map[node]].first);
}
type_map[node] = LOWX;
node = _graph.target(node_data[order_map[xnode]].first);
while (node != root) {
type_map[node] = HIGHX;
node = _graph.target(node_data[order_map[node]].first);
}
type_map[wnode] = PERTINENT;
type_map[root] = ROOT;
}
void findInternalPath(std::vector<Arc>& ipath,
Node wnode, Node root, TypeMap& type_map,
OrderMap& order_map, NodeData& node_data,
ArcLists& arc_lists) {
std::vector<Arc> st;
Node node = wnode;
while (node != root) {
Arc arc = arc_lists[node_data[order_map[node]].first].next;
st.push_back(arc);
node = _graph.target(arc);
}
while (true) {
Arc arc = st.back();
if (type_map[_graph.target(arc)] == LOWX ||
type_map[_graph.target(arc)] == HIGHX) {
break;
}
if (type_map[_graph.target(arc)] == 2) {
type_map[_graph.target(arc)] = 3;
arc = arc_lists[_graph.oppositeArc(arc)].next;
st.push_back(arc);
} else {
st.pop_back();
arc = arc_lists[arc].next;
while (_graph.oppositeArc(arc) == st.back()) {
arc = st.back();
st.pop_back();
arc = arc_lists[arc].next;
}
st.push_back(arc);
}
}
for (int i = 0; i < int(st.size()); ++i) {
if (type_map[_graph.target(st[i])] != LOWY &&
type_map[_graph.target(st[i])] != HIGHY) {
for (; i < int(st.size()); ++i) {
ipath.push_back(st[i]);
}
}
}
}
void setInternalFlags(std::vector<Arc>& ipath, TypeMap& type_map) {
for (int i = 1; i < int(ipath.size()); ++i) {
type_map[_graph.source(ipath[i])] = INTERNAL;
}
}
void findPilePath(std::vector<Arc>& ppath,
Node root, TypeMap& type_map, OrderMap& order_map,
NodeData& node_data, ArcLists& arc_lists) {
std::vector<Arc> st;
st.push_back(_graph.oppositeArc(node_data[order_map[root]].first));
st.push_back(node_data[order_map[root]].first);
while (st.size() > 1) {
Arc arc = st.back();
if (type_map[_graph.target(arc)] == INTERNAL) {
break;
}
if (type_map[_graph.target(arc)] == 3) {
type_map[_graph.target(arc)] = 4;
arc = arc_lists[_graph.oppositeArc(arc)].next;
st.push_back(arc);
} else {
st.pop_back();
arc = arc_lists[arc].next;
while (!st.empty() && _graph.oppositeArc(arc) == st.back()) {
arc = st.back();
st.pop_back();
arc = arc_lists[arc].next;
}
st.push_back(arc);
}
}
for (int i = 1; i < int(st.size()); ++i) {
ppath.push_back(st[i]);
}
}
int markExternalPath(Node node, OrderMap& order_map,
ChildLists& child_lists, PredMap& pred_map,
AncestorMap& ancestor_map, LowMap& low_map) {
int lp = lowPoint(node, order_map, child_lists,
ancestor_map, low_map);
if (ancestor_map[node] != lp) {
node = child_lists[node].first;
_kuratowski[pred_map[node]] = true;
while (ancestor_map[node] != lp) {
for (OutArcIt e(_graph, node); e != INVALID; ++e) {
Node tnode = _graph.target(e);
if (order_map[tnode] > order_map[node] && low_map[tnode] == lp) {
node = tnode;
_kuratowski[e] = true;
break;
}
}
}
}
for (OutArcIt e(_graph, node); e != INVALID; ++e) {
if (order_map[_graph.target(e)] == lp) {
_kuratowski[e] = true;
break;
}
}
return lp;
}
void markPertinentPath(Node node, OrderMap& order_map,
NodeData& node_data, ArcLists& arc_lists,
EmbedArc& embed_arc, MergeRoots& merge_roots) {
while (embed_arc[node] == INVALID) {
int n = merge_roots[node].front();
Arc arc = node_data[n].first;
_kuratowski.set(arc, true);
Node pred = node;
node = _graph.target(arc);
while (!pertinent(node, embed_arc, merge_roots)) {
arc = node_data[order_map[node]].first;
if (_graph.target(arc) == pred) {
arc = arc_lists[arc].next;
}
_kuratowski.set(arc, true);
pred = node;
node = _graph.target(arc);
}
}
_kuratowski.set(embed_arc[node], true);
}
void markPredPath(Node node, Node snode, PredMap& pred_map) {
while (node != snode) {
_kuratowski.set(pred_map[node], true);
node = _graph.source(pred_map[node]);
}
}
void markFacePath(Node ynode, Node xnode,
OrderMap& order_map, NodeData& node_data) {
Arc arc = node_data[order_map[ynode]].first;
Node node = _graph.target(arc);
_kuratowski.set(arc, true);
while (node != xnode) {
arc = node_data[order_map[node]].first;
_kuratowski.set(arc, true);
node = _graph.target(arc);
}
}
void markInternalPath(std::vector<Arc>& path) {
for (int i = 0; i < int(path.size()); ++i) {
_kuratowski.set(path[i], true);
}
}
void markPilePath(std::vector<Arc>& path) {
for (int i = 0; i < int(path.size()); ++i) {
_kuratowski.set(path[i], true);
}
}
void isolateKuratowski(Arc arc, NodeData& node_data,
ArcLists& arc_lists, FlipMap& flip_map,
OrderMap& order_map, OrderList& order_list,
PredMap& pred_map, ChildLists& child_lists,
AncestorMap& ancestor_map, LowMap& low_map,
EmbedArc& embed_arc, MergeRoots& merge_roots) {
Node root = _graph.source(arc);
Node enode = _graph.target(arc);
int rorder = order_map[root];
TypeMap type_map(_graph, 0);
int rn = findComponentRoot(root, enode, child_lists,
order_map, order_list);
Node xnode = order_list[node_data[rn].next];
Node ynode = order_list[node_data[rn].prev];
// Minor-A
{
while (!merge_roots[xnode].empty() || !merge_roots[ynode].empty()) {
if (!merge_roots[xnode].empty()) {
root = xnode;
rn = merge_roots[xnode].front();
} else {
root = ynode;
rn = merge_roots[ynode].front();
}
xnode = order_list[node_data[rn].next];
ynode = order_list[node_data[rn].prev];
}
if (root != _graph.source(arc)) {
orientComponent(root, rn, order_map, pred_map,
node_data, arc_lists, flip_map, type_map);
markFacePath(root, root, order_map, node_data);
int xlp = markExternalPath(xnode, order_map, child_lists,
pred_map, ancestor_map, low_map);
int ylp = markExternalPath(ynode, order_map, child_lists,
pred_map, ancestor_map, low_map);
markPredPath(root, order_list[xlp < ylp ? xlp : ylp], pred_map);
Node lwnode = findPertinent(ynode, order_map, node_data,
embed_arc, merge_roots);
markPertinentPath(lwnode, order_map, node_data, arc_lists,
embed_arc, merge_roots);
return;
}
}
orientComponent(root, rn, order_map, pred_map,
node_data, arc_lists, flip_map, type_map);
Node wnode = findPertinent(ynode, order_map, node_data,
embed_arc, merge_roots);
setFaceFlags(root, wnode, ynode, xnode, order_map, node_data, type_map);
//Minor-B
if (!merge_roots[wnode].empty()) {
int cn = merge_roots[wnode].back();
Node rep = order_list[cn - order_list.size()];
if (low_map[rep] < rorder) {
markFacePath(root, root, order_map, node_data);
int xlp = markExternalPath(xnode, order_map, child_lists,
pred_map, ancestor_map, low_map);
int ylp = markExternalPath(ynode, order_map, child_lists,
pred_map, ancestor_map, low_map);
Node lwnode, lznode;
markCommonPath(wnode, rorder, lwnode, lznode, order_list,
order_map, node_data, arc_lists, embed_arc,
merge_roots, child_lists, ancestor_map, low_map);
markPertinentPath(lwnode, order_map, node_data, arc_lists,
embed_arc, merge_roots);
int zlp = markExternalPath(lznode, order_map, child_lists,
pred_map, ancestor_map, low_map);
int minlp = xlp < ylp ? xlp : ylp;
if (zlp < minlp) minlp = zlp;
int maxlp = xlp > ylp ? xlp : ylp;
if (zlp > maxlp) maxlp = zlp;
markPredPath(order_list[maxlp], order_list[minlp], pred_map);
return;
}
}
Node pxnode, pynode;
std::vector<Arc> ipath;
findInternalPath(ipath, wnode, root, type_map, order_map,
node_data, arc_lists);
setInternalFlags(ipath, type_map);
pynode = _graph.source(ipath.front());
pxnode = _graph.target(ipath.back());
wnode = findPertinent(pynode, order_map, node_data,
embed_arc, merge_roots);
// Minor-C
{
if (type_map[_graph.source(ipath.front())] == HIGHY) {
if (type_map[_graph.target(ipath.back())] == HIGHX) {
markFacePath(xnode, pxnode, order_map, node_data);
}
markFacePath(root, xnode, order_map, node_data);
markPertinentPath(wnode, order_map, node_data, arc_lists,
embed_arc, merge_roots);
markInternalPath(ipath);
int xlp = markExternalPath(xnode, order_map, child_lists,
pred_map, ancestor_map, low_map);
int ylp = markExternalPath(ynode, order_map, child_lists,
pred_map, ancestor_map, low_map);
markPredPath(root, order_list[xlp < ylp ? xlp : ylp], pred_map);
return;
}
if (type_map[_graph.target(ipath.back())] == HIGHX) {
markFacePath(ynode, root, order_map, node_data);
markPertinentPath(wnode, order_map, node_data, arc_lists,
embed_arc, merge_roots);
markInternalPath(ipath);
int xlp = markExternalPath(xnode, order_map, child_lists,
pred_map, ancestor_map, low_map);
int ylp = markExternalPath(ynode, order_map, child_lists,
pred_map, ancestor_map, low_map);
markPredPath(root, order_list[xlp < ylp ? xlp : ylp], pred_map);
return;
}
}
std::vector<Arc> ppath;
findPilePath(ppath, root, type_map, order_map, node_data, arc_lists);
// Minor-D
if (!ppath.empty()) {
markFacePath(ynode, xnode, order_map, node_data);
markPertinentPath(wnode, order_map, node_data, arc_lists,
embed_arc, merge_roots);
markPilePath(ppath);
markInternalPath(ipath);
int xlp = markExternalPath(xnode, order_map, child_lists,
pred_map, ancestor_map, low_map);
int ylp = markExternalPath(ynode, order_map, child_lists,
pred_map, ancestor_map, low_map);
markPredPath(root, order_list[xlp < ylp ? xlp : ylp], pred_map);
return;
}
// Minor-E*
{
if (!external(wnode, rorder, child_lists, ancestor_map, low_map)) {
Node znode = findExternal(pynode, rorder, order_map,
child_lists, ancestor_map,
low_map, node_data);
if (type_map[znode] == LOWY) {
markFacePath(root, xnode, order_map, node_data);
markPertinentPath(wnode, order_map, node_data, arc_lists,
embed_arc, merge_roots);
markInternalPath(ipath);
int xlp = markExternalPath(xnode, order_map, child_lists,
pred_map, ancestor_map, low_map);
int zlp = markExternalPath(znode, order_map, child_lists,
pred_map, ancestor_map, low_map);
markPredPath(root, order_list[xlp < zlp ? xlp : zlp], pred_map);
} else {
markFacePath(ynode, root, order_map, node_data);
markPertinentPath(wnode, order_map, node_data, arc_lists,
embed_arc, merge_roots);
markInternalPath(ipath);
int ylp = markExternalPath(ynode, order_map, child_lists,
pred_map, ancestor_map, low_map);
int zlp = markExternalPath(znode, order_map, child_lists,
pred_map, ancestor_map, low_map);
markPredPath(root, order_list[ylp < zlp ? ylp : zlp], pred_map);
}
return;
}
int xlp = markExternalPath(xnode, order_map, child_lists,
pred_map, ancestor_map, low_map);
int ylp = markExternalPath(ynode, order_map, child_lists,
pred_map, ancestor_map, low_map);
int wlp = markExternalPath(wnode, order_map, child_lists,
pred_map, ancestor_map, low_map);
if (wlp > xlp && wlp > ylp) {
markFacePath(root, root, order_map, node_data);
markPredPath(root, order_list[xlp < ylp ? xlp : ylp], pred_map);
return;
}
markInternalPath(ipath);
markPertinentPath(wnode, order_map, node_data, arc_lists,
embed_arc, merge_roots);
if (xlp > ylp && xlp > wlp) {
markFacePath(root, pynode, order_map, node_data);
markFacePath(wnode, xnode, order_map, node_data);
markPredPath(root, order_list[ylp < wlp ? ylp : wlp], pred_map);
return;
}
if (ylp > xlp && ylp > wlp) {
markFacePath(pxnode, root, order_map, node_data);
markFacePath(ynode, wnode, order_map, node_data);
markPredPath(root, order_list[xlp < wlp ? xlp : wlp], pred_map);
return;
}
if (pynode != ynode) {
markFacePath(pxnode, wnode, order_map, node_data);
int minlp = xlp < ylp ? xlp : ylp;
if (wlp < minlp) minlp = wlp;
int maxlp = xlp > ylp ? xlp : ylp;
if (wlp > maxlp) maxlp = wlp;
markPredPath(order_list[maxlp], order_list[minlp], pred_map);
return;
}
if (pxnode != xnode) {
markFacePath(wnode, pynode, order_map, node_data);
int minlp = xlp < ylp ? xlp : ylp;
if (wlp < minlp) minlp = wlp;
int maxlp = xlp > ylp ? xlp : ylp;
if (wlp > maxlp) maxlp = wlp;
markPredPath(order_list[maxlp], order_list[minlp], pred_map);
return;
}
markFacePath(root, root, order_map, node_data);
int minlp = xlp < ylp ? xlp : ylp;
if (wlp < minlp) minlp = wlp;
markPredPath(root, order_list[minlp], pred_map);
return;
}
}
};
namespace _planarity_bits {
template <typename Graph, typename EmbeddingMap>
void makeConnected(Graph& graph, EmbeddingMap& embedding) {
DfsVisitor<Graph> null_visitor;
DfsVisit<Graph, DfsVisitor<Graph> > dfs(graph, null_visitor);
dfs.init();
typename Graph::Node u = INVALID;
for (typename Graph::NodeIt n(graph); n != INVALID; ++n) {
if (!dfs.reached(n)) {
dfs.addSource(n);
dfs.start();
if (u == INVALID) {
u = n;
} else {
typename Graph::Node v = n;
typename Graph::Arc ue = typename Graph::OutArcIt(graph, u);
typename Graph::Arc ve = typename Graph::OutArcIt(graph, v);
typename Graph::Arc e = graph.direct(graph.addEdge(u, v), true);
if (ue != INVALID) {
embedding[e] = embedding[ue];
embedding[ue] = e;
} else {
embedding[e] = e;
}
if (ve != INVALID) {
embedding[graph.oppositeArc(e)] = embedding[ve];
embedding[ve] = graph.oppositeArc(e);
} else {
embedding[graph.oppositeArc(e)] = graph.oppositeArc(e);
}
}
}
}
}
template <typename Graph, typename EmbeddingMap>
void makeBiNodeConnected(Graph& graph, EmbeddingMap& embedding) {
typename Graph::template ArcMap<bool> processed(graph);
std::vector<typename Graph::Arc> arcs;
for (typename Graph::ArcIt e(graph); e != INVALID; ++e) {
arcs.push_back(e);
}
IterableBoolMap<Graph, typename Graph::Node> visited(graph, false);
for (int i = 0; i < int(arcs.size()); ++i) {
typename Graph::Arc pp = arcs[i];
if (processed[pp]) continue;
typename Graph::Arc e = embedding[graph.oppositeArc(pp)];
processed[e] = true;
visited.set(graph.source(e), true);
typename Graph::Arc p = e, l = e;
e = embedding[graph.oppositeArc(e)];
while (e != l) {
processed[e] = true;
if (visited[graph.source(e)]) {
typename Graph::Arc n =
graph.direct(graph.addEdge(graph.source(p),
graph.target(e)), true);
embedding[n] = p;
embedding[graph.oppositeArc(pp)] = n;
embedding[graph.oppositeArc(n)] =
embedding[graph.oppositeArc(e)];
embedding[graph.oppositeArc(e)] =
graph.oppositeArc(n);
p = n;
e = embedding[graph.oppositeArc(n)];
} else {
visited.set(graph.source(e), true);
pp = p;
p = e;
e = embedding[graph.oppositeArc(e)];
}
}
visited.setAll(false);
}
}
template <typename Graph, typename EmbeddingMap>
void makeMaxPlanar(Graph& graph, EmbeddingMap& embedding) {
typename Graph::template NodeMap<int> degree(graph);
for (typename Graph::NodeIt n(graph); n != INVALID; ++n) {
degree[n] = countIncEdges(graph, n);
}
typename Graph::template ArcMap<bool> processed(graph);
IterableBoolMap<Graph, typename Graph::Node> visited(graph, false);
std::vector<typename Graph::Arc> arcs;
for (typename Graph::ArcIt e(graph); e != INVALID; ++e) {
arcs.push_back(e);
}
for (int i = 0; i < int(arcs.size()); ++i) {
typename Graph::Arc e = arcs[i];
if (processed[e]) continue;
processed[e] = true;
typename Graph::Arc mine = e;
int mind = degree[graph.source(e)];
int face_size = 1;
typename Graph::Arc l = e;
e = embedding[graph.oppositeArc(e)];
while (l != e) {
processed[e] = true;
++face_size;
if (degree[graph.source(e)] < mind) {
mine = e;
mind = degree[graph.source(e)];
}
e = embedding[graph.oppositeArc(e)];
}
if (face_size < 4) {
continue;
}
typename Graph::Node s = graph.source(mine);
for (typename Graph::OutArcIt e(graph, s); e != INVALID; ++e) {
visited.set(graph.target(e), true);
}
typename Graph::Arc oppe = INVALID;
e = embedding[graph.oppositeArc(mine)];
e = embedding[graph.oppositeArc(e)];
while (graph.target(e) != s) {
if (visited[graph.source(e)]) {
oppe = e;
break;
}
e = embedding[graph.oppositeArc(e)];
}
visited.setAll(false);
if (oppe == INVALID) {
e = embedding[graph.oppositeArc(mine)];
typename Graph::Arc pn = mine, p = e;
e = embedding[graph.oppositeArc(e)];
while (graph.target(e) != s) {
typename Graph::Arc n =
graph.direct(graph.addEdge(s, graph.source(e)), true);
embedding[n] = pn;
embedding[graph.oppositeArc(n)] = e;
embedding[graph.oppositeArc(p)] = graph.oppositeArc(n);
pn = n;
p = e;
e = embedding[graph.oppositeArc(e)];
}
embedding[graph.oppositeArc(e)] = pn;
} else {
mine = embedding[graph.oppositeArc(mine)];
s = graph.source(mine);
oppe = embedding[graph.oppositeArc(oppe)];
typename Graph::Node t = graph.source(oppe);
typename Graph::Arc ce = graph.direct(graph.addEdge(s, t), true);
embedding[ce] = mine;
embedding[graph.oppositeArc(ce)] = oppe;
typename Graph::Arc pn = ce, p = oppe;
e = embedding[graph.oppositeArc(oppe)];
while (graph.target(e) != s) {
typename Graph::Arc n =
graph.direct(graph.addEdge(s, graph.source(e)), true);
embedding[n] = pn;
embedding[graph.oppositeArc(n)] = e;
embedding[graph.oppositeArc(p)] = graph.oppositeArc(n);
pn = n;
p = e;
e = embedding[graph.oppositeArc(e)];
}
embedding[graph.oppositeArc(e)] = pn;
pn = graph.oppositeArc(ce), p = mine;
e = embedding[graph.oppositeArc(mine)];
while (graph.target(e) != t) {
typename Graph::Arc n =
graph.direct(graph.addEdge(t, graph.source(e)), true);
embedding[n] = pn;
embedding[graph.oppositeArc(n)] = e;
embedding[graph.oppositeArc(p)] = graph.oppositeArc(n);
pn = n;
p = e;
e = embedding[graph.oppositeArc(e)];
}
embedding[graph.oppositeArc(e)] = pn;
}
}
}
}
/// \ingroup planar
///
/// \brief Schnyder's planar drawing algorithm
///
/// The planar drawing algorithm calculates positions for the nodes
/// in the plane. These coordinates satisfy that if the edges are
/// represented with straight lines, then they will not intersect
/// each other.
///
/// Scnyder's algorithm embeds the graph on an \c (n-2)x(n-2) size grid,
/// i.e. each node will be located in the \c [0..n-2]x[0..n-2] square.
/// The time complexity of the algorithm is O(n).
///
/// \see PlanarEmbedding
template <typename Graph>
class PlanarDrawing {
public:
TEMPLATE_GRAPH_TYPEDEFS(Graph);
/// \brief The point type for storing coordinates
typedef dim2::Point<int> Point;
/// \brief The map type for storing the coordinates of the nodes
typedef typename Graph::template NodeMap<Point> PointMap;
/// \brief Constructor
///
/// Constructor
/// \pre The graph must be simple, i.e. it should not
/// contain parallel or loop arcs.
PlanarDrawing(const Graph& graph)
: _graph(graph), _point_map(graph) {}
private:
template <typename AuxGraph, typename AuxEmbeddingMap>
void drawing(const AuxGraph& graph,
const AuxEmbeddingMap& next,
PointMap& point_map) {
TEMPLATE_GRAPH_TYPEDEFS(AuxGraph);
typename AuxGraph::template ArcMap<Arc> prev(graph);
for (NodeIt n(graph); n != INVALID; ++n) {
Arc e = OutArcIt(graph, n);
Arc p = e, l = e;
e = next[e];
while (e != l) {
prev[e] = p;
p = e;
e = next[e];
}
prev[e] = p;
}
Node anode, bnode, cnode;
{
Arc e = ArcIt(graph);
anode = graph.source(e);
bnode = graph.target(e);
cnode = graph.target(next[graph.oppositeArc(e)]);
}
IterableBoolMap<AuxGraph, Node> proper(graph, false);
typename AuxGraph::template NodeMap<int> conn(graph, -1);
conn[anode] = conn[bnode] = -2;
{
for (OutArcIt e(graph, anode); e != INVALID; ++e) {
Node m = graph.target(e);
if (conn[m] == -1) {
conn[m] = 1;
}
}
conn[cnode] = 2;
for (OutArcIt e(graph, bnode); e != INVALID; ++e) {
Node m = graph.target(e);
if (conn[m] == -1) {
conn[m] = 1;
} else if (conn[m] != -2) {
conn[m] += 1;
Arc pe = graph.oppositeArc(e);
if (conn[graph.target(next[pe])] == -2) {
conn[m] -= 1;
}
if (conn[graph.target(prev[pe])] == -2) {
conn[m] -= 1;
}
proper.set(m, conn[m] == 1);
}
}
}
typename AuxGraph::template ArcMap<int> angle(graph, -1);
while (proper.trueNum() != 0) {
Node n = typename IterableBoolMap<AuxGraph, Node>::TrueIt(proper);
proper.set(n, false);
conn[n] = -2;
for (OutArcIt e(graph, n); e != INVALID; ++e) {
Node m = graph.target(e);
if (conn[m] == -1) {
conn[m] = 1;
} else if (conn[m] != -2) {
conn[m] += 1;
Arc pe = graph.oppositeArc(e);
if (conn[graph.target(next[pe])] == -2) {
conn[m] -= 1;
}
if (conn[graph.target(prev[pe])] == -2) {
conn[m] -= 1;
}
proper.set(m, conn[m] == 1);
}
}
{
Arc e = OutArcIt(graph, n);
Arc p = e, l = e;
e = next[e];
while (e != l) {
if (conn[graph.target(e)] == -2 && conn[graph.target(p)] == -2) {
Arc f = e;
angle[f] = 0;
f = next[graph.oppositeArc(f)];
angle[f] = 1;
f = next[graph.oppositeArc(f)];
angle[f] = 2;
}
p = e;
e = next[e];
}
if (conn[graph.target(e)] == -2 && conn[graph.target(p)] == -2) {
Arc f = e;
angle[f] = 0;
f = next[graph.oppositeArc(f)];
angle[f] = 1;
f = next[graph.oppositeArc(f)];
angle[f] = 2;
}
}
}
typename AuxGraph::template NodeMap<Node> apred(graph, INVALID);
typename AuxGraph::template NodeMap<Node> bpred(graph, INVALID);
typename AuxGraph::template NodeMap<Node> cpred(graph, INVALID);
typename AuxGraph::template NodeMap<int> apredid(graph, -1);
typename AuxGraph::template NodeMap<int> bpredid(graph, -1);
typename AuxGraph::template NodeMap<int> cpredid(graph, -1);
for (ArcIt e(graph); e != INVALID; ++e) {
if (angle[e] == angle[next[e]]) {
switch (angle[e]) {
case 2:
apred[graph.target(e)] = graph.source(e);
apredid[graph.target(e)] = graph.id(graph.source(e));
break;
case 1:
bpred[graph.target(e)] = graph.source(e);
bpredid[graph.target(e)] = graph.id(graph.source(e));
break;
case 0:
cpred[graph.target(e)] = graph.source(e);
cpredid[graph.target(e)] = graph.id(graph.source(e));
break;
}
}
}
cpred[anode] = INVALID;
cpred[bnode] = INVALID;
std::vector<Node> aorder, border, corder;
{
typename AuxGraph::template NodeMap<bool> processed(graph, false);
std::vector<Node> st;
for (NodeIt n(graph); n != INVALID; ++n) {
if (!processed[n] && n != bnode && n != cnode) {
st.push_back(n);
processed[n] = true;
Node m = apred[n];
while (m != INVALID && !processed[m]) {
st.push_back(m);
processed[m] = true;
m = apred[m];
}
while (!st.empty()) {
aorder.push_back(st.back());
st.pop_back();
}
}
}
}
{
typename AuxGraph::template NodeMap<bool> processed(graph, false);
std::vector<Node> st;
for (NodeIt n(graph); n != INVALID; ++n) {
if (!processed[n] && n != cnode && n != anode) {
st.push_back(n);
processed[n] = true;
Node m = bpred[n];
while (m != INVALID && !processed[m]) {
st.push_back(m);
processed[m] = true;
m = bpred[m];
}
while (!st.empty()) {
border.push_back(st.back());
st.pop_back();
}
}
}
}
{
typename AuxGraph::template NodeMap<bool> processed(graph, false);
std::vector<Node> st;
for (NodeIt n(graph); n != INVALID; ++n) {
if (!processed[n] && n != anode && n != bnode) {
st.push_back(n);
processed[n] = true;
Node m = cpred[n];
while (m != INVALID && !processed[m]) {
st.push_back(m);
processed[m] = true;
m = cpred[m];
}
while (!st.empty()) {
corder.push_back(st.back());
st.pop_back();
}
}
}
}
typename AuxGraph::template NodeMap<int> atree(graph, 0);
for (int i = aorder.size() - 1; i >= 0; --i) {
Node n = aorder[i];
atree[n] = 1;
for (OutArcIt e(graph, n); e != INVALID; ++e) {
if (apred[graph.target(e)] == n) {
atree[n] += atree[graph.target(e)];
}
}
}
typename AuxGraph::template NodeMap<int> btree(graph, 0);
for (int i = border.size() - 1; i >= 0; --i) {
Node n = border[i];
btree[n] = 1;
for (OutArcIt e(graph, n); e != INVALID; ++e) {
if (bpred[graph.target(e)] == n) {
btree[n] += btree[graph.target(e)];
}
}
}
typename AuxGraph::template NodeMap<int> apath(graph, 0);
apath[bnode] = apath[cnode] = 1;
typename AuxGraph::template NodeMap<int> apath_btree(graph, 0);
apath_btree[bnode] = btree[bnode];
for (int i = 1; i < int(aorder.size()); ++i) {
Node n = aorder[i];
apath[n] = apath[apred[n]] + 1;
apath_btree[n] = btree[n] + apath_btree[apred[n]];
}
typename AuxGraph::template NodeMap<int> bpath_atree(graph, 0);
bpath_atree[anode] = atree[anode];
for (int i = 1; i < int(border.size()); ++i) {
Node n = border[i];
bpath_atree[n] = atree[n] + bpath_atree[bpred[n]];
}
typename AuxGraph::template NodeMap<int> cpath(graph, 0);
cpath[anode] = cpath[bnode] = 1;
typename AuxGraph::template NodeMap<int> cpath_atree(graph, 0);
cpath_atree[anode] = atree[anode];
typename AuxGraph::template NodeMap<int> cpath_btree(graph, 0);
cpath_btree[bnode] = btree[bnode];
for (int i = 1; i < int(corder.size()); ++i) {
Node n = corder[i];
cpath[n] = cpath[cpred[n]] + 1;
cpath_atree[n] = atree[n] + cpath_atree[cpred[n]];
cpath_btree[n] = btree[n] + cpath_btree[cpred[n]];
}
typename AuxGraph::template NodeMap<int> third(graph);
for (NodeIt n(graph); n != INVALID; ++n) {
point_map[n].x =
bpath_atree[n] + cpath_atree[n] - atree[n] - cpath[n] + 1;
point_map[n].y =
cpath_btree[n] + apath_btree[n] - btree[n] - apath[n] + 1;
}
}
public:
/// \brief Calculate the node positions
///
/// This function calculates the node positions on the plane.
/// \return \c true if the graph is planar.
bool run() {
PlanarEmbedding<Graph> pe(_graph);
if (!pe.run()) return false;
run(pe);
return true;
}
/// \brief Calculate the node positions according to a
/// combinatorical embedding
///
/// This function calculates the node positions on the plane.
/// The given \c embedding map should contain a valid combinatorical
/// embedding, i.e. a valid cyclic order of the arcs.
/// It can be computed using PlanarEmbedding.
template <typename EmbeddingMap>
void run(const EmbeddingMap& embedding) {
typedef SmartEdgeSet<Graph> AuxGraph;
if (3 * countNodes(_graph) - 6 == countEdges(_graph)) {
drawing(_graph, embedding, _point_map);
return;
}
AuxGraph aux_graph(_graph);
typename AuxGraph::template ArcMap<typename AuxGraph::Arc>
aux_embedding(aux_graph);
{
typename Graph::template EdgeMap<typename AuxGraph::Edge>
ref(_graph);
for (EdgeIt e(_graph); e != INVALID; ++e) {
ref[e] = aux_graph.addEdge(_graph.u(e), _graph.v(e));
}
for (EdgeIt e(_graph); e != INVALID; ++e) {
Arc ee = embedding[_graph.direct(e, true)];
aux_embedding[aux_graph.direct(ref[e], true)] =
aux_graph.direct(ref[ee], _graph.direction(ee));
ee = embedding[_graph.direct(e, false)];
aux_embedding[aux_graph.direct(ref[e], false)] =
aux_graph.direct(ref[ee], _graph.direction(ee));
}
}
_planarity_bits::makeConnected(aux_graph, aux_embedding);
_planarity_bits::makeBiNodeConnected(aux_graph, aux_embedding);
_planarity_bits::makeMaxPlanar(aux_graph, aux_embedding);
drawing(aux_graph, aux_embedding, _point_map);
}
/// \brief The coordinate of the given node
///
/// This function returns the coordinate of the given node.
Point operator[](const Node& node) const {
return _point_map[node];
}
/// \brief Return the grid embedding in a node map
///
/// This function returns the grid embedding in a node map of
/// \c dim2::Point<int> coordinates.
const PointMap& coords() const {
return _point_map;
}
private:
const Graph& _graph;
PointMap _point_map;
};
namespace _planarity_bits {
template <typename ColorMap>
class KempeFilter {
public:
typedef typename ColorMap::Key Key;
typedef bool Value;
KempeFilter(const ColorMap& color_map,
const typename ColorMap::Value& first,
const typename ColorMap::Value& second)
: _color_map(color_map), _first(first), _second(second) {}
Value operator[](const Key& key) const {
return _color_map[key] == _first || _color_map[key] == _second;
}
private:
const ColorMap& _color_map;
typename ColorMap::Value _first, _second;
};
}
/// \ingroup planar
///
/// \brief Coloring planar graphs
///
/// The graph coloring problem is the coloring of the graph nodes
/// so that there are no adjacent nodes with the same color. The
/// planar graphs can always be colored with four colors, which is
/// proved by Appel and Haken. Their proofs provide a quadratic
/// time algorithm for four coloring, but it could not be used to
/// implement an efficient algorithm. The five and six coloring can be
/// made in linear time, but in this class, the five coloring has
/// quadratic worst case time complexity. The two coloring (if
/// possible) is solvable with a graph search algorithm and it is
/// implemented in \ref bipartitePartitions() function in LEMON. To
/// decide whether a planar graph is three colorable is NP-complete.
///
/// This class contains member functions for calculate colorings
/// with five and six colors. The six coloring algorithm is a simple
/// greedy coloring on the backward minimum outgoing order of nodes.
/// This order can be computed by selecting the node with least
/// outgoing arcs to unprocessed nodes in each phase. This order
/// guarantees that when a node is chosen for coloring it has at
/// most five already colored adjacents. The five coloring algorithm
/// use the same method, but if the greedy approach fails to color
/// with five colors, i.e. the node has five already different
/// colored neighbours, it swaps the colors in one of the connected
/// two colored sets with the Kempe recoloring method.
template <typename Graph>
class PlanarColoring {
public:
TEMPLATE_GRAPH_TYPEDEFS(Graph);
/// \brief The map type for storing color indices
typedef typename Graph::template NodeMap<int> IndexMap;
/// \brief The map type for storing colors
///
/// The map type for storing colors.
/// \see Palette, Color
typedef ComposeMap<Palette, IndexMap> ColorMap;
/// \brief Constructor
///
/// Constructor.
/// \pre The graph must be simple, i.e. it should not
/// contain parallel or loop arcs.
PlanarColoring(const Graph& graph)
: _graph(graph), _color_map(graph), _palette(0) {
_palette.add(Color(1,0,0));
_palette.add(Color(0,1,0));
_palette.add(Color(0,0,1));
_palette.add(Color(1,1,0));
_palette.add(Color(1,0,1));
_palette.add(Color(0,1,1));
}
/// \brief Return the node map of color indices
///
/// This function returns the node map of color indices. The values are
/// in the range \c [0..4] or \c [0..5] according to the coloring method.
IndexMap colorIndexMap() const {
return _color_map;
}
/// \brief Return the node map of colors
///
/// This function returns the node map of colors. The values are among
/// five or six distinct \ref lemon::Color "colors".
ColorMap colorMap() const {
return composeMap(_palette, _color_map);
}
/// \brief Return the color index of the node
///
/// This function returns the color index of the given node. The value is
/// in the range \c [0..4] or \c [0..5] according to the coloring method.
int colorIndex(const Node& node) const {
return _color_map[node];
}
/// \brief Return the color of the node
///
/// This function returns the color of the given node. The value is among
/// five or six distinct \ref lemon::Color "colors".
Color color(const Node& node) const {
return _palette[_color_map[node]];
}
/// \brief Calculate a coloring with at most six colors
///
/// This function calculates a coloring with at most six colors. The time
/// complexity of this variant is linear in the size of the graph.
/// \return \c true if the algorithm could color the graph with six colors.
/// If the algorithm fails, then the graph is not planar.
/// \note This function can return \c true if the graph is not
/// planar, but it can be colored with at most six colors.
bool runSixColoring() {
typename Graph::template NodeMap<int> heap_index(_graph, -1);
BucketHeap<typename Graph::template NodeMap<int> > heap(heap_index);
for (NodeIt n(_graph); n != INVALID; ++n) {
_color_map[n] = -2;
heap.push(n, countOutArcs(_graph, n));
}
std::vector<Node> order;
while (!heap.empty()) {
Node n = heap.top();
heap.pop();
_color_map[n] = -1;
order.push_back(n);
for (OutArcIt e(_graph, n); e != INVALID; ++e) {
Node t = _graph.runningNode(e);
if (_color_map[t] == -2) {
heap.decrease(t, heap[t] - 1);
}
}
}
for (int i = order.size() - 1; i >= 0; --i) {
std::vector<bool> forbidden(6, false);
for (OutArcIt e(_graph, order[i]); e != INVALID; ++e) {
Node t = _graph.runningNode(e);
if (_color_map[t] != -1) {
forbidden[_color_map[t]] = true;
}
}
for (int k = 0; k < 6; ++k) {
if (!forbidden[k]) {
_color_map[order[i]] = k;
break;
}
}
if (_color_map[order[i]] == -1) {
return false;
}
}
return true;
}
private:
bool recolor(const Node& u, const Node& v) {
int ucolor = _color_map[u];
int vcolor = _color_map[v];
typedef _planarity_bits::KempeFilter<IndexMap> KempeFilter;
KempeFilter filter(_color_map, ucolor, vcolor);
typedef FilterNodes<const Graph, const KempeFilter> KempeGraph;
KempeGraph kempe_graph(_graph, filter);
std::vector<Node> comp;
Bfs<KempeGraph> bfs(kempe_graph);
bfs.init();
bfs.addSource(u);
while (!bfs.emptyQueue()) {
Node n = bfs.nextNode();
if (n == v) return false;
comp.push_back(n);
bfs.processNextNode();
}
int scolor = ucolor + vcolor;
for (int i = 0; i < static_cast<int>(comp.size()); ++i) {
_color_map[comp[i]] = scolor - _color_map[comp[i]];
}
return true;
}
template <typename EmbeddingMap>
void kempeRecoloring(const Node& node, const EmbeddingMap& embedding) {
std::vector<Node> nodes;
nodes.reserve(4);
for (Arc e = OutArcIt(_graph, node); e != INVALID; e = embedding[e]) {
Node t = _graph.target(e);
if (_color_map[t] != -1) {
nodes.push_back(t);
if (nodes.size() == 4) break;
}
}
int color = _color_map[nodes[0]];
if (recolor(nodes[0], nodes[2])) {
_color_map[node] = color;
} else {
color = _color_map[nodes[1]];
recolor(nodes[1], nodes[3]);
_color_map[node] = color;
}
}
public:
/// \brief Calculate a coloring with at most five colors
///
/// This function calculates a coloring with at most five
/// colors. The worst case time complexity of this variant is
/// quadratic in the size of the graph.
/// \param embedding This map should contain a valid combinatorical
/// embedding, i.e. a valid cyclic order of the arcs.
/// It can be computed using PlanarEmbedding.
template <typename EmbeddingMap>
void runFiveColoring(const EmbeddingMap& embedding) {
typename Graph::template NodeMap<int> heap_index(_graph, -1);
BucketHeap<typename Graph::template NodeMap<int> > heap(heap_index);
for (NodeIt n(_graph); n != INVALID; ++n) {
_color_map[n] = -2;
heap.push(n, countOutArcs(_graph, n));
}
std::vector<Node> order;
while (!heap.empty()) {
Node n = heap.top();
heap.pop();
_color_map[n] = -1;
order.push_back(n);
for (OutArcIt e(_graph, n); e != INVALID; ++e) {
Node t = _graph.runningNode(e);
if (_color_map[t] == -2) {
heap.decrease(t, heap[t] - 1);
}
}
}
for (int i = order.size() - 1; i >= 0; --i) {
std::vector<bool> forbidden(5, false);
for (OutArcIt e(_graph, order[i]); e != INVALID; ++e) {
Node t = _graph.runningNode(e);
if (_color_map[t] != -1) {
forbidden[_color_map[t]] = true;
}
}
for (int k = 0; k < 5; ++k) {
if (!forbidden[k]) {
_color_map[order[i]] = k;
break;
}
}
if (_color_map[order[i]] == -1) {
kempeRecoloring(order[i], embedding);
}
}
}
/// \brief Calculate a coloring with at most five colors
///
/// This function calculates a coloring with at most five
/// colors. The worst case time complexity of this variant is
/// quadratic in the size of the graph.
/// \return \c true if the graph is planar.
bool runFiveColoring() {
PlanarEmbedding<Graph> pe(_graph);
if (!pe.run()) return false;
runFiveColoring(pe.embeddingMap());
return true;
}
private:
const Graph& _graph;
IndexMap _color_map;
Palette _palette;
};
}
#endif