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extern/quadriflow/3rd/lemon-1.3.1/lemon/smart_graph.h

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/* -*- 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_SMART_GRAPH_H
#define LEMON_SMART_GRAPH_H
///\ingroup graphs
///\file
///\brief SmartDigraph and SmartGraph classes.
#include <vector>
#include <lemon/core.h>
#include <lemon/error.h>
#include <lemon/bits/graph_extender.h>
namespace lemon {
class SmartDigraph;
class SmartDigraphBase {
protected:
struct NodeT
{
int first_in, first_out;
NodeT() {}
};
struct ArcT
{
int target, source, next_in, next_out;
ArcT() {}
};
std::vector<NodeT> nodes;
std::vector<ArcT> arcs;
public:
typedef SmartDigraphBase Digraph;
class Node;
class Arc;
public:
SmartDigraphBase() : nodes(), arcs() { }
SmartDigraphBase(const SmartDigraphBase &_g)
: nodes(_g.nodes), arcs(_g.arcs) { }
typedef True NodeNumTag;
typedef True ArcNumTag;
int nodeNum() const { return nodes.size(); }
int arcNum() const { return arcs.size(); }
int maxNodeId() const { return nodes.size()-1; }
int maxArcId() const { return arcs.size()-1; }
Node addNode() {
int n = nodes.size();
nodes.push_back(NodeT());
nodes[n].first_in = -1;
nodes[n].first_out = -1;
return Node(n);
}
Arc addArc(Node u, Node v) {
int n = arcs.size();
arcs.push_back(ArcT());
arcs[n].source = u._id;
arcs[n].target = v._id;
arcs[n].next_out = nodes[u._id].first_out;
arcs[n].next_in = nodes[v._id].first_in;
nodes[u._id].first_out = nodes[v._id].first_in = n;
return Arc(n);
}
void clear() {
arcs.clear();
nodes.clear();
}
Node source(Arc a) const { return Node(arcs[a._id].source); }
Node target(Arc a) const { return Node(arcs[a._id].target); }
static int id(Node v) { return v._id; }
static int id(Arc a) { return a._id; }
static Node nodeFromId(int id) { return Node(id);}
static Arc arcFromId(int id) { return Arc(id);}
bool valid(Node n) const {
return n._id >= 0 && n._id < static_cast<int>(nodes.size());
}
bool valid(Arc a) const {
return a._id >= 0 && a._id < static_cast<int>(arcs.size());
}
class Node {
friend class SmartDigraphBase;
friend class SmartDigraph;
protected:
int _id;
explicit Node(int id) : _id(id) {}
public:
Node() {}
Node (Invalid) : _id(-1) {}
bool operator==(const Node i) const {return _id == i._id;}
bool operator!=(const Node i) const {return _id != i._id;}
bool operator<(const Node i) const {return _id < i._id;}
};
class Arc {
friend class SmartDigraphBase;
friend class SmartDigraph;
protected:
int _id;
explicit Arc(int id) : _id(id) {}
public:
Arc() { }
Arc (Invalid) : _id(-1) {}
bool operator==(const Arc i) const {return _id == i._id;}
bool operator!=(const Arc i) const {return _id != i._id;}
bool operator<(const Arc i) const {return _id < i._id;}
};
void first(Node& node) const {
node._id = nodes.size() - 1;
}
static void next(Node& node) {
--node._id;
}
void first(Arc& arc) const {
arc._id = arcs.size() - 1;
}
static void next(Arc& arc) {
--arc._id;
}
void firstOut(Arc& arc, const Node& node) const {
arc._id = nodes[node._id].first_out;
}
void nextOut(Arc& arc) const {
arc._id = arcs[arc._id].next_out;
}
void firstIn(Arc& arc, const Node& node) const {
arc._id = nodes[node._id].first_in;
}
void nextIn(Arc& arc) const {
arc._id = arcs[arc._id].next_in;
}
};
typedef DigraphExtender<SmartDigraphBase> ExtendedSmartDigraphBase;
///\ingroup graphs
///
///\brief A smart directed graph class.
///
///\ref SmartDigraph is a simple and fast digraph implementation.
///It is also quite memory efficient but at the price
///that it does not support node and arc deletion
///(except for the Snapshot feature).
///
///This type fully conforms to the \ref concepts::Digraph "Digraph concept"
///and it also provides some additional functionalities.
///Most of its member functions and nested classes are documented
///only in the concept class.
///
///This class provides constant time counting for nodes and arcs.
///
///\sa concepts::Digraph
///\sa SmartGraph
class SmartDigraph : public ExtendedSmartDigraphBase {
typedef ExtendedSmartDigraphBase Parent;
private:
/// Digraphs are \e not copy constructible. Use DigraphCopy instead.
SmartDigraph(const SmartDigraph &) : ExtendedSmartDigraphBase() {};
/// \brief Assignment of a digraph to another one is \e not allowed.
/// Use DigraphCopy instead.
void operator=(const SmartDigraph &) {}
public:
/// Constructor
/// Constructor.
///
SmartDigraph() {};
///Add a new node to the digraph.
///This function adds a new node to the digraph.
///\return The new node.
Node addNode() { return Parent::addNode(); }
///Add a new arc to the digraph.
///This function adds a new arc to the digraph with source node \c s
///and target node \c t.
///\return The new arc.
Arc addArc(Node s, Node t) {
return Parent::addArc(s, t);
}
/// \brief Node validity check
///
/// This function gives back \c true if the given node is valid,
/// i.e. it is a real node of the digraph.
///
/// \warning A removed node (using Snapshot) could become valid again
/// if new nodes are added to the digraph.
bool valid(Node n) const { return Parent::valid(n); }
/// \brief Arc validity check
///
/// This function gives back \c true if the given arc is valid,
/// i.e. it is a real arc of the digraph.
///
/// \warning A removed arc (using Snapshot) could become valid again
/// if new arcs are added to the graph.
bool valid(Arc a) const { return Parent::valid(a); }
///Split a node.
///This function splits the given node. First, a new node is added
///to the digraph, then the source of each outgoing arc of node \c n
///is moved to this new node.
///If the second parameter \c connect is \c true (this is the default
///value), then a new arc from node \c n to the newly created node
///is also added.
///\return The newly created node.
///
///\note All iterators remain valid.
///
///\warning This functionality cannot be used together with the Snapshot
///feature.
Node split(Node n, bool connect = true)
{
Node b = addNode();
nodes[b._id].first_out=nodes[n._id].first_out;
nodes[n._id].first_out=-1;
for(int i=nodes[b._id].first_out; i!=-1; i=arcs[i].next_out) {
arcs[i].source=b._id;
}
if(connect) addArc(n,b);
return b;
}
///Clear the digraph.
///This function erases all nodes and arcs from the digraph.
///
void clear() {
Parent::clear();
}
/// Reserve memory for nodes.
/// Using this function, it is possible to avoid superfluous memory
/// allocation: if you know that the digraph you want to build will
/// be large (e.g. it will contain millions of nodes and/or arcs),
/// then it is worth reserving space for this amount before starting
/// to build the digraph.
/// \sa reserveArc()
void reserveNode(int n) { nodes.reserve(n); };
/// Reserve memory for arcs.
/// Using this function, it is possible to avoid superfluous memory
/// allocation: if you know that the digraph you want to build will
/// be large (e.g. it will contain millions of nodes and/or arcs),
/// then it is worth reserving space for this amount before starting
/// to build the digraph.
/// \sa reserveNode()
void reserveArc(int m) { arcs.reserve(m); };
public:
class Snapshot;
protected:
void restoreSnapshot(const Snapshot &s)
{
while(s.arc_num<arcs.size()) {
Arc arc = arcFromId(arcs.size()-1);
Parent::notifier(Arc()).erase(arc);
nodes[arcs.back().source].first_out=arcs.back().next_out;
nodes[arcs.back().target].first_in=arcs.back().next_in;
arcs.pop_back();
}
while(s.node_num<nodes.size()) {
Node node = nodeFromId(nodes.size()-1);
Parent::notifier(Node()).erase(node);
nodes.pop_back();
}
}
public:
///Class to make a snapshot of the digraph and to restore it later.
///Class to make a snapshot of the digraph and to restore it later.
///
///The newly added nodes and arcs can be removed using the
///restore() function. This is the only way for deleting nodes and/or
///arcs from a SmartDigraph structure.
///
///\note After a state is restored, you cannot restore a later state,
///i.e. you cannot add the removed nodes and arcs again using
///another Snapshot instance.
///
///\warning Node splitting cannot be restored.
///\warning The validity of the snapshot is not stored due to
///performance reasons. If you do not use the snapshot correctly,
///it can cause broken program, invalid or not restored state of
///the digraph or no change.
class Snapshot
{
SmartDigraph *_graph;
protected:
friend class SmartDigraph;
unsigned int node_num;
unsigned int arc_num;
public:
///Default constructor.
///Default constructor.
///You have to call save() to actually make a snapshot.
Snapshot() : _graph(0) {}
///Constructor that immediately makes a snapshot
///This constructor immediately makes a snapshot of the given digraph.
///
Snapshot(SmartDigraph &gr) : _graph(&gr) {
node_num=_graph->nodes.size();
arc_num=_graph->arcs.size();
}
///Make a snapshot.
///This function makes a snapshot of the given digraph.
///It can be called more than once. In case of a repeated
///call, the previous snapshot gets lost.
void save(SmartDigraph &gr) {
_graph=&gr;
node_num=_graph->nodes.size();
arc_num=_graph->arcs.size();
}
///Undo the changes until a snapshot.
///This function undos the changes until the last snapshot
///created by save() or Snapshot(SmartDigraph&).
void restore()
{
_graph->restoreSnapshot(*this);
}
};
};
class SmartGraphBase {
protected:
struct NodeT {
int first_out;
};
struct ArcT {
int target;
int next_out;
};
std::vector<NodeT> nodes;
std::vector<ArcT> arcs;
public:
typedef SmartGraphBase Graph;
class Node;
class Arc;
class Edge;
class Node {
friend class SmartGraphBase;
protected:
int _id;
explicit Node(int id) { _id = id;}
public:
Node() {}
Node (Invalid) { _id = -1; }
bool operator==(const Node& node) const {return _id == node._id;}
bool operator!=(const Node& node) const {return _id != node._id;}
bool operator<(const Node& node) const {return _id < node._id;}
};
class Edge {
friend class SmartGraphBase;
protected:
int _id;
explicit Edge(int id) { _id = id;}
public:
Edge() {}
Edge (Invalid) { _id = -1; }
bool operator==(const Edge& arc) const {return _id == arc._id;}
bool operator!=(const Edge& arc) const {return _id != arc._id;}
bool operator<(const Edge& arc) const {return _id < arc._id;}
};
class Arc {
friend class SmartGraphBase;
protected:
int _id;
explicit Arc(int id) { _id = id;}
public:
operator Edge() const {
return _id != -1 ? edgeFromId(_id / 2) : INVALID;
}
Arc() {}
Arc (Invalid) { _id = -1; }
bool operator==(const Arc& arc) const {return _id == arc._id;}
bool operator!=(const Arc& arc) const {return _id != arc._id;}
bool operator<(const Arc& arc) const {return _id < arc._id;}
};
SmartGraphBase()
: nodes(), arcs() {}
typedef True NodeNumTag;
typedef True EdgeNumTag;
typedef True ArcNumTag;
int nodeNum() const { return nodes.size(); }
int edgeNum() const { return arcs.size() / 2; }
int arcNum() const { return arcs.size(); }
int maxNodeId() const { return nodes.size()-1; }
int maxEdgeId() const { return arcs.size() / 2 - 1; }
int maxArcId() const { return arcs.size()-1; }
Node source(Arc e) const { return Node(arcs[e._id ^ 1].target); }
Node target(Arc e) const { return Node(arcs[e._id].target); }
Node u(Edge e) const { return Node(arcs[2 * e._id].target); }
Node v(Edge e) const { return Node(arcs[2 * e._id + 1].target); }
static bool direction(Arc e) {
return (e._id & 1) == 1;
}
static Arc direct(Edge e, bool d) {
return Arc(e._id * 2 + (d ? 1 : 0));
}
void first(Node& node) const {
node._id = nodes.size() - 1;
}
static void next(Node& node) {
--node._id;
}
void first(Arc& arc) const {
arc._id = arcs.size() - 1;
}
static void next(Arc& arc) {
--arc._id;
}
void first(Edge& arc) const {
arc._id = arcs.size() / 2 - 1;
}
static void next(Edge& arc) {
--arc._id;
}
void firstOut(Arc &arc, const Node& v) const {
arc._id = nodes[v._id].first_out;
}
void nextOut(Arc &arc) const {
arc._id = arcs[arc._id].next_out;
}
void firstIn(Arc &arc, const Node& v) const {
arc._id = ((nodes[v._id].first_out) ^ 1);
if (arc._id == -2) arc._id = -1;
}
void nextIn(Arc &arc) const {
arc._id = ((arcs[arc._id ^ 1].next_out) ^ 1);
if (arc._id == -2) arc._id = -1;
}
void firstInc(Edge &arc, bool& d, const Node& v) const {
int de = nodes[v._id].first_out;
if (de != -1) {
arc._id = de / 2;
d = ((de & 1) == 1);
} else {
arc._id = -1;
d = true;
}
}
void nextInc(Edge &arc, bool& d) const {
int de = (arcs[(arc._id * 2) | (d ? 1 : 0)].next_out);
if (de != -1) {
arc._id = de / 2;
d = ((de & 1) == 1);
} else {
arc._id = -1;
d = true;
}
}
static int id(Node v) { return v._id; }
static int id(Arc e) { return e._id; }
static int id(Edge e) { return e._id; }
static Node nodeFromId(int id) { return Node(id);}
static Arc arcFromId(int id) { return Arc(id);}
static Edge edgeFromId(int id) { return Edge(id);}
bool valid(Node n) const {
return n._id >= 0 && n._id < static_cast<int>(nodes.size());
}
bool valid(Arc a) const {
return a._id >= 0 && a._id < static_cast<int>(arcs.size());
}
bool valid(Edge e) const {
return e._id >= 0 && 2 * e._id < static_cast<int>(arcs.size());
}
Node addNode() {
int n = nodes.size();
nodes.push_back(NodeT());
nodes[n].first_out = -1;
return Node(n);
}
Edge addEdge(Node u, Node v) {
int n = arcs.size();
arcs.push_back(ArcT());
arcs.push_back(ArcT());
arcs[n].target = u._id;
arcs[n | 1].target = v._id;
arcs[n].next_out = nodes[v._id].first_out;
nodes[v._id].first_out = n;
arcs[n | 1].next_out = nodes[u._id].first_out;
nodes[u._id].first_out = (n | 1);
return Edge(n / 2);
}
void clear() {
arcs.clear();
nodes.clear();
}
};
typedef GraphExtender<SmartGraphBase> ExtendedSmartGraphBase;
/// \ingroup graphs
///
/// \brief A smart undirected graph class.
///
/// \ref SmartGraph is a simple and fast graph implementation.
/// It is also quite memory efficient but at the price
/// that it does not support node and edge deletion
/// (except for the Snapshot feature).
///
/// This type fully conforms to the \ref concepts::Graph "Graph concept"
/// and it also provides some additional functionalities.
/// Most of its member functions and nested classes are documented
/// only in the concept class.
///
/// This class provides constant time counting for nodes, edges and arcs.
///
/// \sa concepts::Graph
/// \sa SmartDigraph
class SmartGraph : public ExtendedSmartGraphBase {
typedef ExtendedSmartGraphBase Parent;
private:
/// Graphs are \e not copy constructible. Use GraphCopy instead.
SmartGraph(const SmartGraph &) : ExtendedSmartGraphBase() {};
/// \brief Assignment of a graph to another one is \e not allowed.
/// Use GraphCopy instead.
void operator=(const SmartGraph &) {}
public:
/// Constructor
/// Constructor.
///
SmartGraph() {}
/// \brief Add a new node to the graph.
///
/// This function adds a new node to the graph.
/// \return The new node.
Node addNode() { return Parent::addNode(); }
/// \brief Add a new edge to the graph.
///
/// This function adds a new edge to the graph between nodes
/// \c u and \c v with inherent orientation from node \c u to
/// node \c v.
/// \return The new edge.
Edge addEdge(Node u, Node v) {
return Parent::addEdge(u, v);
}
/// \brief Node validity check
///
/// This function gives back \c true if the given node is valid,
/// i.e. it is a real node of the graph.
///
/// \warning A removed node (using Snapshot) could become valid again
/// if new nodes are added to the graph.
bool valid(Node n) const { return Parent::valid(n); }
/// \brief Edge validity check
///
/// This function gives back \c true if the given edge is valid,
/// i.e. it is a real edge of the graph.
///
/// \warning A removed edge (using Snapshot) could become valid again
/// if new edges are added to the graph.
bool valid(Edge e) const { return Parent::valid(e); }
/// \brief Arc validity check
///
/// This function gives back \c true if the given arc is valid,
/// i.e. it is a real arc of the graph.
///
/// \warning A removed arc (using Snapshot) could become valid again
/// if new edges are added to the graph.
bool valid(Arc a) const { return Parent::valid(a); }
///Clear the graph.
///This function erases all nodes and arcs from the graph.
///
void clear() {
Parent::clear();
}
/// Reserve memory for nodes.
/// Using this function, it is possible to avoid superfluous memory
/// allocation: if you know that the graph you want to build will
/// be large (e.g. it will contain millions of nodes and/or edges),
/// then it is worth reserving space for this amount before starting
/// to build the graph.
/// \sa reserveEdge()
void reserveNode(int n) { nodes.reserve(n); };
/// Reserve memory for edges.
/// Using this function, it is possible to avoid superfluous memory
/// allocation: if you know that the graph you want to build will
/// be large (e.g. it will contain millions of nodes and/or edges),
/// then it is worth reserving space for this amount before starting
/// to build the graph.
/// \sa reserveNode()
void reserveEdge(int m) { arcs.reserve(2 * m); };
public:
class Snapshot;
protected:
void saveSnapshot(Snapshot &s)
{
s._graph = this;
s.node_num = nodes.size();
s.arc_num = arcs.size();
}
void restoreSnapshot(const Snapshot &s)
{
while(s.arc_num<arcs.size()) {
int n=arcs.size()-1;
Edge arc=edgeFromId(n/2);
Parent::notifier(Edge()).erase(arc);
std::vector<Arc> dir;
dir.push_back(arcFromId(n));
dir.push_back(arcFromId(n-1));
Parent::notifier(Arc()).erase(dir);
nodes[arcs[n-1].target].first_out=arcs[n].next_out;
nodes[arcs[n].target].first_out=arcs[n-1].next_out;
arcs.pop_back();
arcs.pop_back();
}
while(s.node_num<nodes.size()) {
int n=nodes.size()-1;
Node node = nodeFromId(n);
Parent::notifier(Node()).erase(node);
nodes.pop_back();
}
}
public:
///Class to make a snapshot of the graph and to restore it later.
///Class to make a snapshot of the graph and to restore it later.
///
///The newly added nodes and edges can be removed using the
///restore() function. This is the only way for deleting nodes and/or
///edges from a SmartGraph structure.
///
///\note After a state is restored, you cannot restore a later state,
///i.e. you cannot add the removed nodes and edges again using
///another Snapshot instance.
///
///\warning The validity of the snapshot is not stored due to
///performance reasons. If you do not use the snapshot correctly,
///it can cause broken program, invalid or not restored state of
///the graph or no change.
class Snapshot
{
SmartGraph *_graph;
protected:
friend class SmartGraph;
unsigned int node_num;
unsigned int arc_num;
public:
///Default constructor.
///Default constructor.
///You have to call save() to actually make a snapshot.
Snapshot() : _graph(0) {}
///Constructor that immediately makes a snapshot
/// This constructor immediately makes a snapshot of the given graph.
///
Snapshot(SmartGraph &gr) {
gr.saveSnapshot(*this);
}
///Make a snapshot.
///This function makes a snapshot of the given graph.
///It can be called more than once. In case of a repeated
///call, the previous snapshot gets lost.
void save(SmartGraph &gr)
{
gr.saveSnapshot(*this);
}
///Undo the changes until the last snapshot.
///This function undos the changes until the last snapshot
///created by save() or Snapshot(SmartGraph&).
void restore()
{
_graph->restoreSnapshot(*this);
}
};
};
class SmartBpGraphBase {
protected:
struct NodeT {
int first_out;
int partition_next;
int partition_index;
bool red;
};
struct ArcT {
int target;
int next_out;
};
std::vector<NodeT> nodes;
std::vector<ArcT> arcs;
int first_red, first_blue;
int max_red, max_blue;
public:
typedef SmartBpGraphBase Graph;
class Node;
class Arc;
class Edge;
class Node {
friend class SmartBpGraphBase;
protected:
int _id;
explicit Node(int id) { _id = id;}
public:
Node() {}
Node (Invalid) { _id = -1; }
bool operator==(const Node& node) const {return _id == node._id;}
bool operator!=(const Node& node) const {return _id != node._id;}
bool operator<(const Node& node) const {return _id < node._id;}
};
class RedNode : public Node {
friend class SmartBpGraphBase;
protected:
explicit RedNode(int pid) : Node(pid) {}
public:
RedNode() {}
RedNode(const RedNode& node) : Node(node) {}
RedNode(Invalid) : Node(INVALID){}
};
class BlueNode : public Node {
friend class SmartBpGraphBase;
protected:
explicit BlueNode(int pid) : Node(pid) {}
public:
BlueNode() {}
BlueNode(const BlueNode& node) : Node(node) {}
BlueNode(Invalid) : Node(INVALID){}
};
class Edge {
friend class SmartBpGraphBase;
protected:
int _id;
explicit Edge(int id) { _id = id;}
public:
Edge() {}
Edge (Invalid) { _id = -1; }
bool operator==(const Edge& arc) const {return _id == arc._id;}
bool operator!=(const Edge& arc) const {return _id != arc._id;}
bool operator<(const Edge& arc) const {return _id < arc._id;}
};
class Arc {
friend class SmartBpGraphBase;
protected:
int _id;
explicit Arc(int id) { _id = id;}
public:
operator Edge() const {
return _id != -1 ? edgeFromId(_id / 2) : INVALID;
}
Arc() {}
Arc (Invalid) { _id = -1; }
bool operator==(const Arc& arc) const {return _id == arc._id;}
bool operator!=(const Arc& arc) const {return _id != arc._id;}
bool operator<(const Arc& arc) const {return _id < arc._id;}
};
SmartBpGraphBase()
: nodes(), arcs(), first_red(-1), first_blue(-1),
max_red(-1), max_blue(-1) {}
typedef True NodeNumTag;
typedef True EdgeNumTag;
typedef True ArcNumTag;
int nodeNum() const { return nodes.size(); }
int redNum() const { return max_red + 1; }
int blueNum() const { return max_blue + 1; }
int edgeNum() const { return arcs.size() / 2; }
int arcNum() const { return arcs.size(); }
int maxNodeId() const { return nodes.size()-1; }
int maxRedId() const { return max_red; }
int maxBlueId() const { return max_blue; }
int maxEdgeId() const { return arcs.size() / 2 - 1; }
int maxArcId() const { return arcs.size()-1; }
bool red(Node n) const { return nodes[n._id].red; }
bool blue(Node n) const { return !nodes[n._id].red; }
static RedNode asRedNodeUnsafe(Node n) { return RedNode(n._id); }
static BlueNode asBlueNodeUnsafe(Node n) { return BlueNode(n._id); }
Node source(Arc a) const { return Node(arcs[a._id ^ 1].target); }
Node target(Arc a) const { return Node(arcs[a._id].target); }
RedNode redNode(Edge e) const {
return RedNode(arcs[2 * e._id].target);
}
BlueNode blueNode(Edge e) const {
return BlueNode(arcs[2 * e._id + 1].target);
}
static bool direction(Arc a) {
return (a._id & 1) == 1;
}
static Arc direct(Edge e, bool d) {
return Arc(e._id * 2 + (d ? 1 : 0));
}
void first(Node& node) const {
node._id = nodes.size() - 1;
}
static void next(Node& node) {
--node._id;
}
void first(RedNode& node) const {
node._id = first_red;
}
void next(RedNode& node) const {
node._id = nodes[node._id].partition_next;
}
void first(BlueNode& node) const {
node._id = first_blue;
}
void next(BlueNode& node) const {
node._id = nodes[node._id].partition_next;
}
void first(Arc& arc) const {
arc._id = arcs.size() - 1;
}
static void next(Arc& arc) {
--arc._id;
}
void first(Edge& arc) const {
arc._id = arcs.size() / 2 - 1;
}
static void next(Edge& arc) {
--arc._id;
}
void firstOut(Arc &arc, const Node& v) const {
arc._id = nodes[v._id].first_out;
}
void nextOut(Arc &arc) const {
arc._id = arcs[arc._id].next_out;
}
void firstIn(Arc &arc, const Node& v) const {
arc._id = ((nodes[v._id].first_out) ^ 1);
if (arc._id == -2) arc._id = -1;
}
void nextIn(Arc &arc) const {
arc._id = ((arcs[arc._id ^ 1].next_out) ^ 1);
if (arc._id == -2) arc._id = -1;
}
void firstInc(Edge &arc, bool& d, const Node& v) const {
int de = nodes[v._id].first_out;
if (de != -1) {
arc._id = de / 2;
d = ((de & 1) == 1);
} else {
arc._id = -1;
d = true;
}
}
void nextInc(Edge &arc, bool& d) const {
int de = (arcs[(arc._id * 2) | (d ? 1 : 0)].next_out);
if (de != -1) {
arc._id = de / 2;
d = ((de & 1) == 1);
} else {
arc._id = -1;
d = true;
}
}
static int id(Node v) { return v._id; }
int id(RedNode v) const { return nodes[v._id].partition_index; }
int id(BlueNode v) const { return nodes[v._id].partition_index; }
static int id(Arc e) { return e._id; }
static int id(Edge e) { return e._id; }
static Node nodeFromId(int id) { return Node(id);}
static Arc arcFromId(int id) { return Arc(id);}
static Edge edgeFromId(int id) { return Edge(id);}
bool valid(Node n) const {
return n._id >= 0 && n._id < static_cast<int>(nodes.size());
}
bool valid(Arc a) const {
return a._id >= 0 && a._id < static_cast<int>(arcs.size());
}
bool valid(Edge e) const {
return e._id >= 0 && 2 * e._id < static_cast<int>(arcs.size());
}
RedNode addRedNode() {
int n = nodes.size();
nodes.push_back(NodeT());
nodes[n].first_out = -1;
nodes[n].red = true;
nodes[n].partition_index = ++max_red;
nodes[n].partition_next = first_red;
first_red = n;
return RedNode(n);
}
BlueNode addBlueNode() {
int n = nodes.size();
nodes.push_back(NodeT());
nodes[n].first_out = -1;
nodes[n].red = false;
nodes[n].partition_index = ++max_blue;
nodes[n].partition_next = first_blue;
first_blue = n;
return BlueNode(n);
}
Edge addEdge(RedNode u, BlueNode v) {
int n = arcs.size();
arcs.push_back(ArcT());
arcs.push_back(ArcT());
arcs[n].target = u._id;
arcs[n | 1].target = v._id;
arcs[n].next_out = nodes[v._id].first_out;
nodes[v._id].first_out = n;
arcs[n | 1].next_out = nodes[u._id].first_out;
nodes[u._id].first_out = (n | 1);
return Edge(n / 2);
}
void clear() {
arcs.clear();
nodes.clear();
first_red = -1;
first_blue = -1;
max_blue = -1;
max_red = -1;
}
};
typedef BpGraphExtender<SmartBpGraphBase> ExtendedSmartBpGraphBase;
/// \ingroup graphs
///
/// \brief A smart undirected bipartite graph class.
///
/// \ref SmartBpGraph is a simple and fast bipartite graph implementation.
/// It is also quite memory efficient but at the price
/// that it does not support node and edge deletion
/// (except for the Snapshot feature).
///
/// This type fully conforms to the \ref concepts::BpGraph "BpGraph concept"
/// and it also provides some additional functionalities.
/// Most of its member functions and nested classes are documented
/// only in the concept class.
///
/// This class provides constant time counting for nodes, edges and arcs.
///
/// \sa concepts::BpGraph
/// \sa SmartGraph
class SmartBpGraph : public ExtendedSmartBpGraphBase {
typedef ExtendedSmartBpGraphBase Parent;
private:
/// Graphs are \e not copy constructible. Use GraphCopy instead.
SmartBpGraph(const SmartBpGraph &) : ExtendedSmartBpGraphBase() {};
/// \brief Assignment of a graph to another one is \e not allowed.
/// Use GraphCopy instead.
void operator=(const SmartBpGraph &) {}
public:
/// Constructor
/// Constructor.
///
SmartBpGraph() {}
/// \brief Add a new red node to the graph.
///
/// This function adds a red new node to the graph.
/// \return The new node.
RedNode addRedNode() { return Parent::addRedNode(); }
/// \brief Add a new blue node to the graph.
///
/// This function adds a blue new node to the graph.
/// \return The new node.
BlueNode addBlueNode() { return Parent::addBlueNode(); }
/// \brief Add a new edge to the graph.
///
/// This function adds a new edge to the graph between nodes
/// \c u and \c v with inherent orientation from node \c u to
/// node \c v.
/// \return The new edge.
Edge addEdge(RedNode u, BlueNode v) {
return Parent::addEdge(u, v);
}
Edge addEdge(BlueNode v, RedNode u) {
return Parent::addEdge(u, v);
}
/// \brief Node validity check
///
/// This function gives back \c true if the given node is valid,
/// i.e. it is a real node of the graph.
///
/// \warning A removed node (using Snapshot) could become valid again
/// if new nodes are added to the graph.
bool valid(Node n) const { return Parent::valid(n); }
/// \brief Edge validity check
///
/// This function gives back \c true if the given edge is valid,
/// i.e. it is a real edge of the graph.
///
/// \warning A removed edge (using Snapshot) could become valid again
/// if new edges are added to the graph.
bool valid(Edge e) const { return Parent::valid(e); }
/// \brief Arc validity check
///
/// This function gives back \c true if the given arc is valid,
/// i.e. it is a real arc of the graph.
///
/// \warning A removed arc (using Snapshot) could become valid again
/// if new edges are added to the graph.
bool valid(Arc a) const { return Parent::valid(a); }
///Clear the graph.
///This function erases all nodes and arcs from the graph.
///
void clear() {
Parent::clear();
}
/// Reserve memory for nodes.
/// Using this function, it is possible to avoid superfluous memory
/// allocation: if you know that the graph you want to build will
/// be large (e.g. it will contain millions of nodes and/or edges),
/// then it is worth reserving space for this amount before starting
/// to build the graph.
/// \sa reserveEdge()
void reserveNode(int n) { nodes.reserve(n); };
/// Reserve memory for edges.
/// Using this function, it is possible to avoid superfluous memory
/// allocation: if you know that the graph you want to build will
/// be large (e.g. it will contain millions of nodes and/or edges),
/// then it is worth reserving space for this amount before starting
/// to build the graph.
/// \sa reserveNode()
void reserveEdge(int m) { arcs.reserve(2 * m); };
public:
class Snapshot;
protected:
void saveSnapshot(Snapshot &s)
{
s._graph = this;
s.node_num = nodes.size();
s.arc_num = arcs.size();
}
void restoreSnapshot(const Snapshot &s)
{
while(s.arc_num<arcs.size()) {
int n=arcs.size()-1;
Edge arc=edgeFromId(n/2);
Parent::notifier(Edge()).erase(arc);
std::vector<Arc> dir;
dir.push_back(arcFromId(n));
dir.push_back(arcFromId(n-1));
Parent::notifier(Arc()).erase(dir);
nodes[arcs[n-1].target].first_out=arcs[n].next_out;
nodes[arcs[n].target].first_out=arcs[n-1].next_out;
arcs.pop_back();
arcs.pop_back();
}
while(s.node_num<nodes.size()) {
int n=nodes.size()-1;
Node node = nodeFromId(n);
if (Parent::red(node)) {
first_red = nodes[n].partition_next;
if (first_red != -1) {
max_red = nodes[first_red].partition_index;
} else {
max_red = -1;
}
Parent::notifier(RedNode()).erase(asRedNodeUnsafe(node));
} else {
first_blue = nodes[n].partition_next;
if (first_blue != -1) {
max_blue = nodes[first_blue].partition_index;
} else {
max_blue = -1;
}
Parent::notifier(BlueNode()).erase(asBlueNodeUnsafe(node));
}
Parent::notifier(Node()).erase(node);
nodes.pop_back();
}
}
public:
///Class to make a snapshot of the graph and to restore it later.
///Class to make a snapshot of the graph and to restore it later.
///
///The newly added nodes and edges can be removed using the
///restore() function. This is the only way for deleting nodes and/or
///edges from a SmartBpGraph structure.
///
///\note After a state is restored, you cannot restore a later state,
///i.e. you cannot add the removed nodes and edges again using
///another Snapshot instance.
///
///\warning The validity of the snapshot is not stored due to
///performance reasons. If you do not use the snapshot correctly,
///it can cause broken program, invalid or not restored state of
///the graph or no change.
class Snapshot
{
SmartBpGraph *_graph;
protected:
friend class SmartBpGraph;
unsigned int node_num;
unsigned int arc_num;
public:
///Default constructor.
///Default constructor.
///You have to call save() to actually make a snapshot.
Snapshot() : _graph(0) {}
///Constructor that immediately makes a snapshot
/// This constructor immediately makes a snapshot of the given graph.
///
Snapshot(SmartBpGraph &gr) {
gr.saveSnapshot(*this);
}
///Make a snapshot.
///This function makes a snapshot of the given graph.
///It can be called more than once. In case of a repeated
///call, the previous snapshot gets lost.
void save(SmartBpGraph &gr)
{
gr.saveSnapshot(*this);
}
///Undo the changes until the last snapshot.
///This function undos the changes until the last snapshot
///created by save() or Snapshot(SmartBpGraph&).
void restore()
{
_graph->restoreSnapshot(*this);
}
};
};
} //namespace lemon
#endif //LEMON_SMART_GRAPH_H