graph.h

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// Undirected graphs
class TUNGraph;
class TBPGraph;
//TODO:class TUNEGraph; -- undirected multigraph

typedef TPt<TUNGraph> PUNGraph;
typedef TPt<TBPGraph> PBPGraph;

// Directed graphs
class TNGraph;
class TNEGraph;

typedef TPt<TNGraph> PNGraph;
typedef TPt<TNEGraph> PNEGraph;


class TUNGraph {
public:
  typedef TUNGraph TNet;
  typedef TPt<TUNGraph> PNet;
public:
  class TNode {
  private:
    TInt Id;
    TIntV NIdV;
  public:
    TNode() : Id(-1), NIdV() { }
    TNode(const int& NId) : Id(NId), NIdV() { }
    TNode(const TNode& Node) : Id(Node.Id), NIdV(Node.NIdV) { }
    TNode(TSIn& SIn) : Id(SIn), NIdV(SIn) { }
    void Save(TSOut& SOut) const { Id.Save(SOut);  NIdV.Save(SOut); }
    int GetId() const { return Id; }
    int GetDeg() const { return NIdV.Len(); }
    int GetInDeg() const { return GetDeg(); }
    int GetOutDeg() const { return GetDeg(); }
    int GetInNId(const int& NodeN) const { return GetNbrNId(NodeN); }
    int GetOutNId(const int& NodeN) const { return GetNbrNId(NodeN); }
    int GetNbrNId(const int& NodeN) const { return NIdV[NodeN]; }
    bool IsNbrNId(const int& NId) const { return NIdV.SearchBin(NId)!=-1; }
    bool IsInNId(const int& NId) const { return IsNbrNId(NId); }
    bool IsOutNId(const int& NId) const { return IsNbrNId(NId); }
    void PackOutNIdV() { NIdV.Pack(); }
    void PackNIdV() { NIdV.Pack(); }
    friend class TUNGraph;
    friend class TUNGraphMtx;
  };
  class TNodeI {
  private:
    typedef THash<TInt, TNode>::TIter THashIter;
    THashIter NodeHI;
  public:
    TNodeI() : NodeHI() { }
    TNodeI(const THashIter& NodeHIter) : NodeHI(NodeHIter) { }
    TNodeI(const TNodeI& NodeI) : NodeHI(NodeI.NodeHI) { }
    TNodeI& operator = (const TNodeI& NodeI) { NodeHI = NodeI.NodeHI;  return *this; }

    TNodeI& operator++ (int) { NodeHI++;  return *this; }

    bool operator < (const TNodeI& NodeI) const { return NodeHI < NodeI.NodeHI; }
    bool operator == (const TNodeI& NodeI) const { return NodeHI == NodeI.NodeHI; }

    int GetId() const { return NodeHI.GetDat().GetId(); }
    int GetDeg() const { return NodeHI.GetDat().GetDeg(); }
    int GetInDeg() const { return NodeHI.GetDat().GetInDeg(); }
    int GetOutDeg() const { return NodeHI.GetDat().GetOutDeg(); }

    int GetInNId(const int& NodeN) const { return NodeHI.GetDat().GetInNId(NodeN); }

    int GetOutNId(const int& NodeN) const { return NodeHI.GetDat().GetOutNId(NodeN); }

    int GetNbrNId(const int& NodeN) const { return NodeHI.GetDat().GetNbrNId(NodeN); }
    bool IsInNId(const int& NId) const { return NodeHI.GetDat().IsInNId(NId); }
    bool IsOutNId(const int& NId) const { return NodeHI.GetDat().IsOutNId(NId); }
    bool IsNbrNId(const int& NId) const { return NodeHI.GetDat().IsNbrNId(NId); }
    friend class TUNGraph;
  };
  class TEdgeI {
  private:
    TNodeI CurNode, EndNode;
    int CurEdge;
  public:
    TEdgeI() : CurNode(), EndNode(), CurEdge(0) { }
    TEdgeI(const TNodeI& NodeI, const TNodeI& EndNodeI, const int& EdgeN=0) : CurNode(NodeI), EndNode(EndNodeI), CurEdge(EdgeN) { }
    TEdgeI(const TEdgeI& EdgeI) : CurNode(EdgeI.CurNode), EndNode(EdgeI.EndNode), CurEdge(EdgeI.CurEdge) { }
    TEdgeI& operator = (const TEdgeI& EdgeI) { if (this!=&EdgeI) { CurNode=EdgeI.CurNode;  EndNode=EdgeI.EndNode;  CurEdge=EdgeI.CurEdge; }  return *this; }
    TEdgeI& operator++ (int) { do { CurEdge++; if (CurEdge >= CurNode.GetOutDeg()) { CurEdge=0;  CurNode++; while (CurNode < EndNode && CurNode.GetOutDeg()==0) { CurNode++; } } } while (CurNode < EndNode && GetSrcNId()>GetDstNId()); return *this; }
    bool operator < (const TEdgeI& EdgeI) const { return CurNode<EdgeI.CurNode || (CurNode==EdgeI.CurNode && CurEdge<EdgeI.CurEdge); }
    bool operator == (const TEdgeI& EdgeI) const { return CurNode == EdgeI.CurNode && CurEdge == EdgeI.CurEdge; }
    int GetId() const { return -1; }
    int GetSrcNId() const { return CurNode.GetId(); }
    int GetDstNId() const { return CurNode.GetOutNId(CurEdge); }
    friend class TUNGraph;
  };
private:
  TCRef CRef;
  TInt MxNId;
  THash<TInt, TNode> NodeH;
private:
  TNode& GetNode(const int& NId) { return NodeH.GetDat(NId); }
  const TNode& GetNode(const int& NId) const { return NodeH.GetDat(NId); }
public:
  TUNGraph() : CRef(), MxNId(0), NodeH() { }
  explicit TUNGraph(const int& Nodes, const int& Edges) : MxNId(0) { Reserve(Nodes, Edges); }
  TUNGraph(const TUNGraph& Graph) : MxNId(Graph.MxNId), NodeH(Graph.NodeH) { }
  TUNGraph(TSIn& SIn) : MxNId(SIn), NodeH(SIn) { }
  void Save(TSOut& SOut) const { MxNId.Save(SOut);  NodeH.Save(SOut); }
  static PUNGraph New() { return new TUNGraph(); }

  static PUNGraph New(const int& Nodes, const int& Edges) { return new TUNGraph(Nodes, Edges); }
  static PUNGraph Load(TSIn& SIn) { return PUNGraph(new TUNGraph(SIn)); }
  bool HasFlag(const TGraphFlag& Flag) const;
  TUNGraph& operator = (const TUNGraph& Graph) {
    if (this!=&Graph) { MxNId=Graph.MxNId;  NodeH=Graph.NodeH; }  return *this; }
  
  int GetNodes() const { return NodeH.Len(); }

  int AddNode(int NId = -1);
  int AddNode(const TNodeI& NodeI) { return AddNode(NodeI.GetId()); }

  int AddNode(const int& NId, const TIntV& NbrNIdV);

  int AddNode(const int& NId, const TVecPool<TInt>& Pool, const int& NIdVId);

  void DelNode(const int& NId);
  void DelNode(const TNode& NodeI) { DelNode(NodeI.GetId()); }
  bool IsNode(const int& NId) const { return NodeH.IsKey(NId); }
  TNodeI BegNI() const { return TNodeI(NodeH.BegI()); }
  TNodeI EndNI() const { return TNodeI(NodeH.EndI()); }
  TNodeI GetNI(const int& NId) const { return TNodeI(NodeH.GetI(NId)); }
  int GetMxNId() const { return MxNId; }

  int GetEdges() const;

  int AddEdge(const int& SrcNId, const int& DstNId);
  int AddEdge(const TEdgeI& EdgeI) { return AddEdge(EdgeI.GetSrcNId(), EdgeI.GetDstNId()); }

  void DelEdge(const int& SrcNId, const int& DstNId);
  bool IsEdge(const int& SrcNId, const int& DstNId) const;
  TEdgeI BegEI() const { TNodeI NI=BegNI(); while (NI<EndNI() && (NI.GetOutDeg()==0 || NI.GetId()>NI.GetOutNId(0))) { NI++; } return TEdgeI(NI, EndNI()); }
  TEdgeI EndEI() const { return TEdgeI(EndNI(), EndNI()); }
  TEdgeI GetEI(const int& EId) const;

  TEdgeI GetEI(const int& SrcNId, const int& DstNId) const;

  int GetRndNId(TRnd& Rnd=TInt::Rnd) { return NodeH.GetKey(NodeH.GetRndKeyId(Rnd, 0.8)); }
  TNodeI GetRndNI(TRnd& Rnd=TInt::Rnd) { return GetNI(GetRndNId(Rnd)); }
  void GetNIdV(TIntV& NIdV) const;

  bool Empty() const { return GetNodes()==0; }
  void Clr() { MxNId=0;  NodeH.Clr(); }
  void Reserve(const int& Nodes, const int& Edges) { if (Nodes>0) NodeH.Gen(Nodes/2); }
  void ReserveNIdDeg(const int& NId, const int& Deg) { GetNode(NId).NIdV.Reserve(Deg); }

  void Defrag(const bool& OnlyNodeLinks=false);

  bool IsOk(const bool& ThrowExcept=true) const;
  void Dump(FILE *OutF=stdout) const;

  static PUNGraph GetSmallGraph();

  friend class TUNGraphMtx;
  friend class TPt<TUNGraph>;
};

// Directed Node Graph


class TNGraph {
public:
  typedef TNGraph TNet;
  typedef TPt<TNGraph> PNet;
public:
  class TNode {
  private:
    TInt Id;
    TIntV InNIdV, OutNIdV;
  public:
    TNode() : Id(-1), InNIdV(), OutNIdV() { }
    TNode(const int& NId) : Id(NId), InNIdV(), OutNIdV() { }
    TNode(const TNode& Node) : Id(Node.Id), InNIdV(Node.InNIdV), OutNIdV(Node.OutNIdV) { }
    TNode(TSIn& SIn) : Id(SIn), InNIdV(SIn), OutNIdV(SIn) { }
    void Save(TSOut& SOut) const { Id.Save(SOut);  InNIdV.Save(SOut);  OutNIdV.Save(SOut);  }
    int GetId() const { return Id; }
    int GetDeg() const { return GetInDeg() + GetOutDeg(); }
    int GetInDeg() const { return InNIdV.Len(); }
    int GetOutDeg() const { return OutNIdV.Len(); }
    int GetInNId(const int& NodeN) const { return InNIdV[NodeN]; }
    int GetOutNId(const int& NodeN) const { return OutNIdV[NodeN]; }
    int GetNbrNId(const int& NodeN) const { return NodeN<GetOutDeg()?GetOutNId(NodeN):GetInNId(NodeN-GetOutDeg()); }
    bool IsInNId(const int& NId) const { return InNIdV.SearchBin(NId) != -1; }
    bool IsOutNId(const int& NId) const { return OutNIdV.SearchBin(NId) != -1; }
    bool IsNbrNId(const int& NId) const { return IsOutNId(NId) || IsInNId(NId); }
    void PackOutNIdV() { OutNIdV.Pack(); }
    void PackNIdV() { InNIdV.Pack(); }
    friend class TNGraph;
    friend class TNGraphMtx;
  };
  class TNodeI {
  private:
    typedef THash<TInt, TNode>::TIter THashIter;
    THashIter NodeHI;
  public:
    TNodeI() : NodeHI() { }
    TNodeI(const THashIter& NodeHIter) : NodeHI(NodeHIter) { }
    TNodeI(const TNodeI& NodeI) : NodeHI(NodeI.NodeHI) { }
    TNodeI& operator = (const TNodeI& NodeI) { NodeHI = NodeI.NodeHI;  return *this; }
    TNodeI& operator++ (int) { NodeHI++;  return *this; }
    bool operator < (const TNodeI& NodeI) const { return NodeHI < NodeI.NodeHI; }
    bool operator == (const TNodeI& NodeI) const { return NodeHI == NodeI.NodeHI; }
    int GetId() const { return NodeHI.GetDat().GetId(); }
    int GetDeg() const { return NodeHI.GetDat().GetDeg(); }
    int GetInDeg() const { return NodeHI.GetDat().GetInDeg(); }
    int GetOutDeg() const { return NodeHI.GetDat().GetOutDeg(); }

    int GetInNId(const int& NodeN) const { return NodeHI.GetDat().GetInNId(NodeN); }

    int GetOutNId(const int& NodeN) const { return NodeHI.GetDat().GetOutNId(NodeN); }

    int GetNbrNId(const int& NodeN) const { return NodeHI.GetDat().GetNbrNId(NodeN); }
    bool IsInNId(const int& NId) const { return NodeHI.GetDat().IsInNId(NId); }
    bool IsOutNId(const int& NId) const { return NodeHI.GetDat().IsOutNId(NId); }
    bool IsNbrNId(const int& NId) const { return IsOutNId(NId) || IsInNId(NId); }
    friend class TNGraph;
  };
  class TEdgeI {
  private:
    TNodeI CurNode, EndNode;
    int CurEdge;
  public:
    TEdgeI() : CurNode(), EndNode(), CurEdge(0) { }
    TEdgeI(const TNodeI& NodeI, const TNodeI& EndNodeI, const int& EdgeN=0) : CurNode(NodeI), EndNode(EndNodeI), CurEdge(EdgeN) { }
    TEdgeI(const TEdgeI& EdgeI) : CurNode(EdgeI.CurNode), EndNode(EdgeI.EndNode), CurEdge(EdgeI.CurEdge) { }
    TEdgeI& operator = (const TEdgeI& EdgeI) { if (this!=&EdgeI) { CurNode=EdgeI.CurNode;  EndNode=EdgeI.EndNode;  CurEdge=EdgeI.CurEdge; }  return *this; }
    TEdgeI& operator++ (int) { CurEdge++; if (CurEdge >= CurNode.GetOutDeg()) { CurEdge=0;  CurNode++;
      while (CurNode < EndNode && CurNode.GetOutDeg()==0) { CurNode++; } }  return *this; }
    bool operator < (const TEdgeI& EdgeI) const { return CurNode<EdgeI.CurNode || (CurNode==EdgeI.CurNode && CurEdge<EdgeI.CurEdge); }
    bool operator == (const TEdgeI& EdgeI) const { return CurNode == EdgeI.CurNode && CurEdge == EdgeI.CurEdge; }
    int GetId() const { return -1; }
    int GetSrcNId() const { return CurNode.GetId(); }
    int GetDstNId() const { return CurNode.GetOutNId(CurEdge); }
    friend class TNGraph;
  };
private:
  TCRef CRef;
  TInt MxNId;
  THash<TInt, TNode> NodeH;
private:
  TNode& GetNode(const int& NId) { return NodeH.GetDat(NId); }
  const TNode& GetNode(const int& NId) const { return NodeH.GetDat(NId); }
public:
  TNGraph() : CRef(), MxNId(0), NodeH() { }
  explicit TNGraph(const int& Nodes, const int& Edges) : MxNId(0) { Reserve(Nodes, Edges); }
  TNGraph(const TNGraph& Graph) : MxNId(Graph.MxNId), NodeH(Graph.NodeH) { }
  TNGraph(TSIn& SIn) : MxNId(SIn), NodeH(SIn) { }
  void Save(TSOut& SOut) const { MxNId.Save(SOut);  NodeH.Save(SOut); }
  static PNGraph New() { return new TNGraph(); }

  static PNGraph New(const int& Nodes, const int& Edges) { return new TNGraph(Nodes, Edges); }
  static PNGraph Load(TSIn& SIn) { return PNGraph(new TNGraph(SIn)); }
  bool HasFlag(const TGraphFlag& Flag) const;
  TNGraph& operator = (const TNGraph& Graph) {
    if (this!=&Graph) { MxNId=Graph.MxNId;  NodeH=Graph.NodeH; }  return *this; }
  
  int GetNodes() const { return NodeH.Len(); }

  int AddNode(int NId = -1);
  int AddNode(const TNodeI& NodeId) { return AddNode(NodeId.GetId()); }

  int AddNode(const int& NId, const TIntV& InNIdV, const TIntV& OutNIdV);

  int AddNode(const int& NId, const TVecPool<TInt>& Pool, const int& SrcVId, const int& DstVId);

  void DelNode(const int& NId);
  void DelNode(const TNode& NodeI) { DelNode(NodeI.GetId()); }
  bool IsNode(const int& NId) const { return NodeH.IsKey(NId); }
  TNodeI BegNI() const { return TNodeI(NodeH.BegI()); }
  TNodeI EndNI() const { return TNodeI(NodeH.EndI()); }
  TNodeI GetNI(const int& NId) const { return TNodeI(NodeH.GetI(NId)); }
  // GetNodeC() has been commented out. It was a quick shortcut, do not use.
  //const TNode& GetNodeC(const int& NId) const { return NodeH.GetDat(NId); }
  int GetMxNId() const { return MxNId; }

  int GetEdges() const;

  int AddEdge(const int& SrcNId, const int& DstNId);
  int AddEdge(const TEdgeI& EdgeI) { return AddEdge(EdgeI.GetSrcNId(), EdgeI.GetDstNId()); }

  void DelEdge(const int& SrcNId, const int& DstNId, const bool& IsDir = true);
  bool IsEdge(const int& SrcNId, const int& DstNId, const bool& IsDir = true) const;
  TEdgeI BegEI() const { TNodeI NI=BegNI();  while(NI<EndNI() && NI.GetOutDeg()==0) NI++;  return TEdgeI(NI, EndNI()); }
  TEdgeI EndEI() const { return TEdgeI(EndNI(), EndNI()); }
  TEdgeI GetEI(const int& EId) const; // not supported
  TEdgeI GetEI(const int& SrcNId, const int& DstNId) const;

  int GetRndNId(TRnd& Rnd=TInt::Rnd) { return NodeH.GetKey(NodeH.GetRndKeyId(Rnd, 0.8)); }
  TNodeI GetRndNI(TRnd& Rnd=TInt::Rnd) { return GetNI(GetRndNId(Rnd)); }
  void GetNIdV(TIntV& NIdV) const;

  bool Empty() const { return GetNodes()==0; }
  void Clr() { MxNId=0;  NodeH.Clr(); }
  void Reserve(const int& Nodes, const int& Edges) { if (Nodes>0) { NodeH.Gen(Nodes/2); } }
  void ReserveNIdInDeg(const int& NId, const int& InDeg) { GetNode(NId).InNIdV.Reserve(InDeg); }
  void ReserveNIdOutDeg(const int& NId, const int& OutDeg) { GetNode(NId).OutNIdV.Reserve(OutDeg); }

  void Defrag(const bool& OnlyNodeLinks=false);

  bool IsOk(const bool& ThrowExcept=true) const;
  void Dump(FILE *OutF=stdout) const;

  static PNGraph GetSmallGraph();
  friend class TPt<TNGraph>;
  friend class TNGraphMtx;
};

// set flags
namespace TSnap {
template <> struct IsDirected<TNGraph> { enum { Val = 1 }; };
}

// Node Edge Graph

// TODO TNEGraph describe time complexity for basic operations

class TNEGraph {
public:
  typedef TNEGraph TNet;
  typedef TPt<TNEGraph> PNet;
public:
  class TNode {
  private:
    TInt Id;
    TIntV InEIdV, OutEIdV;
  public:
    TNode() : Id(-1), InEIdV(), OutEIdV() { }
    TNode(const int& NId) : Id(NId), InEIdV(), OutEIdV() { }
    TNode(const TNode& Node) : Id(Node.Id), InEIdV(Node.InEIdV), OutEIdV(Node.OutEIdV) { }
    TNode(TSIn& SIn) : Id(SIn), InEIdV(SIn), OutEIdV(SIn) { }
    void Save(TSOut& SOut) const { Id.Save(SOut);  InEIdV.Save(SOut);  OutEIdV.Save(SOut);  }
    int GetId() const { return Id; }
    int GetDeg() const { return GetInDeg() + GetOutDeg(); }
    int GetInDeg() const { return InEIdV.Len(); }
    int GetOutDeg() const { return OutEIdV.Len(); }
    int GetInEId(const int& EdgeN) const { return InEIdV[EdgeN]; }
    int GetOutEId(const int& EdgeN) const { return OutEIdV[EdgeN]; }
    int GetNbrEId(const int& EdgeN) const { return EdgeN<GetOutDeg()?GetOutEId(EdgeN):GetInEId(EdgeN-GetOutDeg()); }
    bool IsInEId(const int& EId) const { return InEIdV.SearchBin(EId) != -1; }
    bool IsOutEId(const int& EId) const { return OutEIdV.SearchBin(EId) != -1; }
    friend class TNEGraph;
  };
  class TEdge {
  private:
    TInt Id, SrcNId, DstNId;
  public:
    TEdge() : Id(-1), SrcNId(-1), DstNId(-1) { }
    TEdge(const int& EId, const int& SourceNId, const int& DestNId) : Id(EId), SrcNId(SourceNId), DstNId(DestNId) { }
    TEdge(const TEdge& Edge) : Id(Edge.Id), SrcNId(Edge.SrcNId), DstNId(Edge.DstNId) { }
    TEdge(TSIn& SIn) : Id(SIn), SrcNId(SIn), DstNId(SIn) { }
    void Save(TSOut& SOut) const { Id.Save(SOut);  SrcNId.Save(SOut);  DstNId.Save(SOut); }
    int GetId() const { return Id; }
    int GetSrcNId() const { return SrcNId; }
    int GetDstNId() const { return DstNId; }
    friend class TNEGraph;
  };
  class TNodeI {
  private:
    typedef THash<TInt, TNode>::TIter THashIter;
    THashIter NodeHI;
    const TNEGraph *Graph;
  public:
    TNodeI() : NodeHI(), Graph(NULL) { }
    TNodeI(const THashIter& NodeHIter, const TNEGraph* GraphPt) : NodeHI(NodeHIter), Graph(GraphPt) { }
    TNodeI(const TNodeI& NodeI) : NodeHI(NodeI.NodeHI), Graph(NodeI.Graph) { }
    TNodeI& operator = (const TNodeI& NodeI) { NodeHI = NodeI.NodeHI;  Graph=NodeI.Graph;  return *this; }
    TNodeI& operator++ (int) { NodeHI++;  return *this; }
    bool operator < (const TNodeI& NodeI) const { return NodeHI < NodeI.NodeHI; }
    bool operator == (const TNodeI& NodeI) const { return NodeHI == NodeI.NodeHI; }
    int GetId() const { return NodeHI.GetDat().GetId(); }
    int GetDeg() const { return NodeHI.GetDat().GetDeg(); }
    int GetInDeg() const { return NodeHI.GetDat().GetInDeg(); }
    int GetOutDeg() const { return NodeHI.GetDat().GetOutDeg(); }

    int GetInNId(const int& EdgeN) const { return Graph->GetEdge(NodeHI.GetDat().GetInEId(EdgeN)).GetSrcNId(); }

    int GetOutNId(const int& EdgeN) const { return Graph->GetEdge(NodeHI.GetDat().GetOutEId(EdgeN)).GetDstNId(); }

    int GetNbrNId(const int& EdgeN) const { const TEdge& E = Graph->GetEdge(NodeHI.GetDat().GetNbrEId(EdgeN));
      return GetId()==E.GetSrcNId() ? E.GetDstNId():E.GetSrcNId(); }
    bool IsInNId(const int& NId) const;
    bool IsOutNId(const int& NId) const;
    bool IsNbrNId(const int& NId) const { return IsOutNId(NId) || IsInNId(NId); }
    // edges
    int GetInEId(const int& EdgeN) const { return NodeHI.GetDat().GetInEId(EdgeN); }
    int GetOutEId(const int& EdgeN) const { return NodeHI.GetDat().GetOutEId(EdgeN); }
    int GetNbrEId(const int& EdgeN) const { return NodeHI.GetDat().GetNbrEId(EdgeN); }
    bool IsInEId(const int& EId) const { return NodeHI.GetDat().IsInEId(EId); }
    bool IsOutEId(const int& EId) const { return NodeHI.GetDat().IsOutEId(EId); }
    bool IsNbrEId(const int& EId) const { return IsInEId(EId) || IsOutEId(EId); }
    friend class TNEGraph;
  };
  class TEdgeI {
  private:
    typedef THash<TInt, TEdge>::TIter THashIter;
    THashIter EdgeHI;
    const TNEGraph *Graph;
  public:
    TEdgeI() : EdgeHI(), Graph(NULL) { }
    TEdgeI(const THashIter& EdgeHIter, const TNEGraph *GraphPt) : EdgeHI(EdgeHIter), Graph(GraphPt) { }
    TEdgeI(const TEdgeI& EdgeI) : EdgeHI(EdgeI.EdgeHI), Graph(EdgeI.Graph) { }
    TEdgeI& operator = (const TEdgeI& EdgeI) { if (this!=&EdgeI) { EdgeHI=EdgeI.EdgeHI;  Graph=EdgeI.Graph; }  return *this; }
    TEdgeI& operator++ (int) { EdgeHI++;  return *this; }
    bool operator < (const TEdgeI& EdgeI) const { return EdgeHI < EdgeI.EdgeHI; }
    bool operator == (const TEdgeI& EdgeI) const { return EdgeHI == EdgeI.EdgeHI; }
    int GetId() const { return EdgeHI.GetDat().GetId(); }
    int GetSrcNId() const { return EdgeHI.GetDat().GetSrcNId(); }
    int GetDstNId() const { return EdgeHI.GetDat().GetDstNId(); }
    friend class TNEGraph;
  };

private:
  TNode& GetNode(const int& NId) { return NodeH.GetDat(NId); }
  const TNode& GetNode(const int& NId) const { return NodeH.GetDat(NId); }
  TEdge& GetEdge(const int& EId) { return EdgeH.GetDat(EId); }
  const TEdge& GetEdge(const int& EId) const { return EdgeH.GetDat(EId); }
private:
  TCRef CRef;
  TInt MxNId, MxEId;
  THash<TInt, TNode> NodeH;
  THash<TInt, TEdge> EdgeH;
public:
  TNEGraph() : CRef(), MxNId(0), MxEId(0) { }
  explicit TNEGraph(const int& Nodes, const int& Edges) : CRef(), MxNId(0), MxEId(0) { Reserve(Nodes, Edges); }
  TNEGraph(const TNEGraph& Graph) : MxNId(Graph.MxNId), MxEId(Graph.MxEId), NodeH(Graph.NodeH), EdgeH(Graph.EdgeH) { }
  TNEGraph(TSIn& SIn) : MxNId(SIn), MxEId(SIn), NodeH(SIn), EdgeH(SIn) { }
  void Save(TSOut& SOut) const { MxNId.Save(SOut);  MxEId.Save(SOut);  NodeH.Save(SOut);  EdgeH.Save(SOut); }
  static PNEGraph New() { return PNEGraph(new TNEGraph()); }

  static PNEGraph New(const int& Nodes, const int& Edges) { return PNEGraph(new TNEGraph(Nodes, Edges)); }
  static PNEGraph Load(TSIn& SIn) { return PNEGraph(new TNEGraph(SIn)); }
  bool HasFlag(const TGraphFlag& Flag) const;
  TNEGraph& operator = (const TNEGraph& Graph) { if (this!=&Graph) {
    MxNId=Graph.MxNId; MxEId=Graph.MxEId; NodeH=Graph.NodeH; EdgeH=Graph.EdgeH; }  return *this; }

  int GetNodes() const { return NodeH.Len(); }

  int AddNode(int NId = -1);
  int AddNode(const TNodeI& NodeId) { return AddNode(NodeId.GetId()); }

  void DelNode(const int& NId);
  void DelNode(const TNode& NodeI) { DelNode(NodeI.GetId()); }
  bool IsNode(const int& NId) const { return NodeH.IsKey(NId); }
  TNodeI BegNI() const { return TNodeI(NodeH.BegI(), this); }
  TNodeI EndNI() const { return TNodeI(NodeH.EndI(), this); }
  TNodeI GetNI(const int& NId) const { return TNodeI(NodeH.GetI(NId), this); }
  int GetMxNId() const { return MxNId; }

  int GetEdges() const { return EdgeH.Len(); }

  int AddEdge(const int& SrcNId, const int& DstNId, int EId  = -1);
  int AddEdge(const TEdgeI& EdgeI) { return AddEdge(EdgeI.GetSrcNId(), EdgeI.GetDstNId(), EdgeI.GetId()); }
  void DelEdge(const int& EId);

  void DelEdge(const int& SrcNId, const int& DstNId, const bool& IsDir = true);
  bool IsEdge(const int& EId) const { return EdgeH.IsKey(EId); }
  bool IsEdge(const int& SrcNId, const int& DstNId, const bool& IsDir = true) const { int EId;  return IsEdge(SrcNId, DstNId, EId, IsDir); }
  bool IsEdge(const int& SrcNId, const int& DstNId, int& EId, const bool& IsDir = true) const;
  int GetEId(const int& SrcNId, const int& DstNId) const { int EId; return IsEdge(SrcNId, DstNId, EId)?EId:-1; }
  TEdgeI BegEI() const { return TEdgeI(EdgeH.BegI(), this); }
  TEdgeI EndEI() const { return TEdgeI(EdgeH.EndI(), this); }
  // TODO document TNEGraph::GetEI()
  TEdgeI GetEI(const int& EId) const { return TEdgeI(EdgeH.GetI(EId), this); }
  // TODO document TNEGraph::GetEI()
  TEdgeI GetEI(const int& SrcNId, const int& DstNId) const { return GetEI(GetEId(SrcNId, DstNId)); }

  int GetRndNId(TRnd& Rnd=TInt::Rnd) { return NodeH.GetKey(NodeH.GetRndKeyId(Rnd, 0.8)); }
  TNodeI GetRndNI(TRnd& Rnd=TInt::Rnd) { return GetNI(GetRndNId(Rnd)); }
  int GetRndEId(TRnd& Rnd=TInt::Rnd) { return EdgeH.GetKey(EdgeH.GetRndKeyId(Rnd, 0.8)); }
  TEdgeI GetRndEI(TRnd& Rnd=TInt::Rnd) { return GetEI(GetRndEId(Rnd)); }
  void GetNIdV(TIntV& NIdV) const;
  void GetEIdV(TIntV& EIdV) const;

  bool Empty() const { return GetNodes()==0; }
  void Clr() { MxNId=0;  MxEId=0;  NodeH.Clr();  EdgeH.Clr(); }
  void Reserve(const int& Nodes, const int& Edges) {
    if (Nodes>0) NodeH.Gen(Nodes/2);  if (Edges>0) EdgeH.Gen(Edges/2); }

  void Defrag(const bool& OnlyNodeLinks=false);

  bool IsOk(const bool& ThrowExcept=true) const;
  void Dump(FILE *OutF=stdout) const;
  // TODO implement and document TNEGraph::GetSmallGraph()
  static PNEGraph GetSmallGraph();
  friend class TPt<TNEGraph>;
};

// set flags
namespace TSnap {
template <> struct IsMultiGraph<TNEGraph> { enum { Val = 1 }; };
template <> struct IsDirected<TNEGraph> { enum { Val = 1 }; };
}


class TBPGraph {
public:
  typedef TBPGraph TNet;
  typedef TPt<TBPGraph> PNet;
  typedef enum { bgsUndef, bgsLeft, bgsRight, bgsBoth } TNodeTy; // left or right hand side node
public:
  class TNode {
  private:
    TInt Id;
    TIntV NIdV;
    TNodeTy NodeTy; // remove
  public:
    TNode() : Id(-1), NIdV(), NodeTy(bgsUndef) { }
    TNode(const int& NId) : Id(NId), NIdV(), NodeTy(true?bgsLeft:bgsRight) { }
    TNode(const TNode& Node) : Id(Node.Id), NIdV(Node.NIdV), NodeTy(Node.NodeTy) { }
    TNode(TSIn& SIn) : Id(SIn), NIdV(SIn), NodeTy(bgsUndef) { TInt Ty(SIn);  NodeTy=(TNodeTy)Ty.Val; }
    void Save(TSOut& SOut) const { Id.Save(SOut);  NIdV.Save(SOut);  TInt(NodeTy).Save(SOut); }
    int GetId() const { return Id; }
    int GetDeg() const { return NIdV.Len(); }
    int GetInDeg() const { return GetDeg(); }
    int GetOutDeg() const { return GetDeg(); }
    int GetInNId(const int& NodeN) const { return GetNbrNId(NodeN); }
    int GetOutNId(const int& NodeN) const { return GetNbrNId(NodeN); }
    int GetNbrNId(const int& NodeN) const { return NIdV[NodeN]; }
    bool IsNbrNId(const int& NId) const { return NIdV.SearchBin(NId)!=-1; }
    bool IsInNId(const int& NId) const { return IsNbrNId(NId); }
    bool IsOutNId(const int& NId) const { return IsNbrNId(NId); }
    void PackOutNIdV() { NIdV.Pack(); }
    void PackNIdV() { NIdV.Pack(); }
    friend class TBPGraph;
  };
  class TNodeI {
  private:
    typedef THash<TInt, TNode>::TIter THashIter;
    THashIter LeftHI, RightHI; // iterator over left and right hand-side nodes
  private:
    inline THashIter HI() const { return ! LeftHI.IsEnd()?LeftHI:RightHI; }
  public:
    TNodeI() : LeftHI(), RightHI() { }
    TNodeI(const THashIter& LeftHIter, const THashIter& RightHIter) : LeftHI(LeftHIter), RightHI(RightHIter) { }
    TNodeI(const TNodeI& NodeI) : LeftHI(NodeI.LeftHI), RightHI(NodeI.RightHI) { }
    TNodeI& operator = (const TNodeI& NodeI) { LeftHI = NodeI.LeftHI;  RightHI=NodeI.RightHI;  return *this; }
    TNodeI& operator++ (int) { 
      if (! LeftHI.IsEnd()) { 
        LeftHI++; } 
      else if (! RightHI.IsEnd()) { 
        RightHI++; } 
      return *this; }
    bool operator < (const TNodeI& NodeI) const { return LeftHI < NodeI.LeftHI || (LeftHI==NodeI.LeftHI && RightHI < NodeI.RightHI); }
    bool operator == (const TNodeI& NodeI) const { return LeftHI==NodeI.LeftHI && RightHI==NodeI.RightHI; }
    int GetId() const { return HI().GetDat().GetId(); }
    bool IsLeft() const { return ! LeftHI.IsEnd(); }
    bool IsRight() const { return ! IsLeft(); }
    int GetDeg() const { return HI().GetDat().GetDeg(); }
    int GetInDeg() const { return HI().GetDat().GetInDeg(); }
    int GetOutDeg() const { return HI().GetDat().GetOutDeg(); }

    int GetInNId(const int& NodeN) const { return HI().GetDat().GetInNId(NodeN); }

    int GetOutNId(const int& NodeN) const { return HI().GetDat().GetOutNId(NodeN); }

    int GetNbrNId(const int& NodeN) const { return HI().GetDat().GetNbrNId(NodeN); }
    bool IsInNId(const int& NId) const { return HI().GetDat().IsInNId(NId); }
    bool IsOutNId(const int& NId) const { return HI().GetDat().IsOutNId(NId); }
    bool IsNbrNId(const int& NId) const { return HI().GetDat().IsNbrNId(NId); }
    friend class TBPGraph;
  };
  class TEdgeI {
  private:
    TNodeI CurNode, EndNode; // end node on the 'left'
    int CurEdge;
  public:
    TEdgeI() : CurNode(), EndNode(), CurEdge(0) { }
    TEdgeI(const TNodeI& NodeI, const TNodeI& EndNodeI, const int& EdgeN=0) : CurNode(NodeI), EndNode(EndNodeI), CurEdge(EdgeN) { }
    TEdgeI(const TEdgeI& EdgeI) : CurNode(EdgeI.CurNode), EndNode(EdgeI.EndNode), CurEdge(EdgeI.CurEdge) { }
    TEdgeI& operator = (const TEdgeI& EdgeI) { if (this!=&EdgeI) { CurNode=EdgeI.CurNode;  EndNode=EdgeI.EndNode;  CurEdge=EdgeI.CurEdge; }  return *this; }
    TEdgeI& operator++ (int) { CurEdge++; if (CurEdge >= CurNode.GetOutDeg()) { CurEdge=0;  CurNode++;
      while (CurNode < EndNode && CurNode.GetOutDeg()==0) { CurNode++; } }  return *this; }
    bool operator < (const TEdgeI& EdgeI) const { return CurNode<EdgeI.CurNode || (CurNode==EdgeI.CurNode && CurEdge<EdgeI.CurEdge); }
    bool operator == (const TEdgeI& EdgeI) const { return CurNode == EdgeI.CurNode && CurEdge == EdgeI.CurEdge; }
    int GetId() const { return -1; }
    int GetSrcNId() const { return CurNode.GetId(); }
    int GetDstNId() const { return CurNode.GetOutNId(CurEdge); }
    int GetLNId() const { return GetSrcNId(); }
    int GetRNId() const { return GetDstNId(); }
    friend class TBPGraph;
  };
private:
  TCRef CRef;
  TInt MxNId;                 // maximum node id in the graph
  THash<TInt, TNode> LeftH;   // 'left' nodes
  THash<TInt, TNode> RightH;  // 'right' nodes
private:
  //TNode& GetNode(const int& NId) { return NodeH.GetDat(NId); }
  //const TNode& GetNode(const int& NId) const { return NodeH.GetDat(NId); }
public:
  TBPGraph() : CRef(), MxNId(0), LeftH(), RightH() { }
  explicit TBPGraph(const int& Nodes, const int& Edges) : MxNId(0) { } 
  TBPGraph(const TBPGraph& BPGraph) : MxNId(BPGraph.MxNId), LeftH(BPGraph.LeftH), RightH(BPGraph.RightH) { }
  TBPGraph(TSIn& SIn) : MxNId(SIn), LeftH(SIn), RightH(SIn) { }
  void Save(TSOut& SOut) const { MxNId.Save(SOut);  LeftH.Save(SOut);  RightH.Save(SOut); }
  static PBPGraph New() { return new TBPGraph(); }

  static PBPGraph New(const int& Nodes, const int& Edges) { return new TBPGraph(Nodes, Edges); }
  static PBPGraph Load(TSIn& SIn) { return PBPGraph(new TBPGraph(SIn)); }
  bool HasFlag(const TGraphFlag& Flag) const;
  TBPGraph& operator = (const TBPGraph& BPGraph) {
    if (this!=&BPGraph) { MxNId=BPGraph.MxNId;  LeftH=BPGraph.LeftH;  RightH=BPGraph.RightH; }  return *this; }
  
  int GetNodes() const { return GetLNodes() + GetRNodes(); }
  int GetLNodes() const { return LeftH.Len(); }
  int GetRNodes() const { return RightH.Len(); }

  int AddNode(int NId = -1, const bool& LeftNode=true);
  int AddNode(const TNodeI& NodeI) { return AddNode(NodeI.GetId(), NodeI.IsLeft()); }

  void DelNode(const int& NId);
  void DelNode(const TNode& NodeI) { DelNode(NodeI.GetId()); }
  bool IsNode(const int& NId) const { return IsLNode(NId) || IsRNode(NId); }
  bool IsLNode(const int& NId) const { return LeftH.IsKey(NId); }
  bool IsRNode(const int& NId) const { return RightH.IsKey(NId); }
  int GetMxNId() const { return MxNId; }
    
  TNodeI BegNI() const { return TNodeI(LeftH.BegI(), RightH.BegI()); }
  TNodeI EndNI() const { return TNodeI(LeftH.EndI(), RightH.EndI()); }
  TNodeI GetNI(const int& NId) const { return IsLNode(NId) ? TNodeI(LeftH.GetI(NId), RightH.EndI()) : TNodeI(LeftH.EndI(), RightH.GetI(NId)); }
  TNodeI BegLNI() const { return TNodeI(LeftH.BegI(), RightH.EndI()); }
  TNodeI EndLNI() const { return EndNI(); }
  TNodeI BegRNI() const { return TNodeI(LeftH.EndI(), RightH.BegI()); }
  TNodeI EndRNI() const { return EndNI(); }

  int GetEdges() const;

  int AddEdge(const int& LeftNId, const int& RightNId);
  int AddEdge(const TEdgeI& EdgeI) { return AddEdge(EdgeI.GetSrcNId(), EdgeI.GetDstNId()); }

  void DelEdge(const int& LeftNId, const int& RightNId);
  bool IsEdge(const int& LeftNId, const int& RightNId) const;
  TEdgeI BegEI() const { TNodeI NI=BegLNI(); while (NI<EndLNI() && (NI.GetOutDeg()==0 || NI.GetId()>NI.GetOutNId(0))) { NI++; } return TEdgeI(NI, EndLNI()); }
  TEdgeI EndEI() const { return TEdgeI(EndNI(), EndNI()); }
  TEdgeI GetEI(const int& EId) const;

  TEdgeI GetEI(const int& LeftNId, const int& RightNId) const;
    
  int GetRndNId(TRnd& Rnd=TInt::Rnd);
  int GetRndLNId(TRnd& Rnd=TInt::Rnd);
  int GetRndRNId(TRnd& Rnd=TInt::Rnd);
  TNodeI GetRndNI(TRnd& Rnd=TInt::Rnd) { return GetNI(GetRndNId(Rnd)); }
  void GetNIdV(TIntV& NIdV) const;
  void GetLNIdV(TIntV& NIdV) const;
  void GetRNIdV(TIntV& NIdV) const;

  bool Empty() const { return GetNodes()==0; }
  void Clr() { MxNId=0;  LeftH.Clr();  RightH.Clr(); }
  void Reserve(const int& Nodes, const int& Edges);

  void Defrag(const bool& OnlyNodeLinks=false);

  bool IsOk(const bool& ThrowExcept=true) const;
  void Dump(FILE *OutF=stdout) const;

  static PBPGraph GetSmallGraph();

  friend class TPt<TBPGraph>;
};

// set flags
namespace TSnap {
template <> struct IsBipart<TBPGraph> { enum { Val = 1 }; };
}