C++ PNGraph::GetRndNId方法代码示例

void analyzeSimNetProps() {
	const char *eFName = "epidemicRoutingNetEdges.txt";
	const char *pFName = "prophetRoutingNetEdges.txt";

	PNGraph eGraph = TSnap::LoadEdgeListStr<PNGraph>(eFName, 0, 1);
        PNEGraph pGraph = TSnap::LoadEdgeListStr<PNEGraph>(pFName, 0, 1);
        PNGraph randGraph = TSnap::GenRndGnm<PNGraph>(eGraph->GetNodes(), eGraph->GetEdges(), true, TInt::Rnd);

	chdir("dot");

	for (int i=0; i<10; i++) {
		TIntV NIdV;
		for (int j = 0; j < 10; j++) {
			int randNode = eGraph->GetRndNId();
			NIdV.AddUnique(randNode);
		}

		// Plot the mesage propagtion in Endroy-Renyi graphs
		PNGraph randFlow = TSnap::GetSubGraph<PNGraph>(randGraph, NIdV);
		char randf[50]; sprintf(randf,"%d-erdos.dot",i);
                TSnap::SaveGViz(randFlow, randf, TStr("Edros-Renyi random graph"));

		// Now plot epidemic routing
		PNGraph epidemicFlow = TSnap::GetSubGraph<PNGraph>(eGraph, NIdV);
		char epf[50]; sprintf(epf,"%d-epidemic.dot",i);
  		TSnap::SaveGViz(epidemicFlow, epf, TStr("Epidemic routing"));
	}

}

// Test node, edge creation
void ManipulateNodesEdges() {
  int NNodes = 10000;
  int NEdges = 100000;
  const char *FName = "demo.graph.dat";

  PNGraph Graph;
  PNGraph Graph1;
  PNGraph Graph2;
  int i;
  int n;
  int NCount;
  int ECount1;
  int ECount2;
  int x,y;
  bool t;

  Graph = TNGraph::New();
  t = Graph->Empty();

  // create the nodes
  for (i = 0; i < NNodes; i++) {
    Graph->AddNode(i);
  }
  t = Graph->Empty();
  n = Graph->GetNodes();

  // create random edges
  NCount = NEdges;
  while (NCount > 0) {
    x = rand() % NNodes;
    y = rand() % NNodes;
    // Graph->GetEdges() is not correct for the loops (x == y),
    // skip the loops in this test
    if (x != y  &&  !Graph->IsEdge(x,y)) {
      n = Graph->AddEdge(x, y);
      NCount--;
    }
  }
  PrintGStats("ManipulateNodesEdges:Graph",Graph);

  // get all the nodes
  NCount = 0;
  for (TNGraph::TNodeI NI = Graph->BegNI(); NI < Graph->EndNI(); NI++) {
    NCount++;
  }

  // get all the edges for all the nodes
  ECount1 = 0;
  for (TNGraph::TNodeI NI = Graph->BegNI(); NI < Graph->EndNI(); NI++) {
    for (int e = 0; e < NI.GetOutDeg(); e++) {
      ECount1++;
    }
  }

  // get all the edges directly
  ECount2 = 0;
  for (TNGraph::TEdgeI EI = Graph->BegEI(); EI < Graph->EndEI(); EI++) {
    ECount2++;
  }
  printf("ManipulateNodesEdges:Graph, nodes %d, edges1 %d, edges2 %d\n",
      NCount, ECount1, ECount2);

  // assignment
  Graph1 = TNGraph::New();
  *Graph1 = *Graph;
  PrintGStats("ManipulateNodesEdges:Graph1",Graph1);

  // save the graph
  {
    TFOut FOut(FName);
    Graph->Save(FOut);
    FOut.Flush();
  }

  // load the graph
  {
    TFIn FIn(FName);
    Graph2 = TNGraph::Load(FIn);
  }
  PrintGStats("ManipulateNodesEdges:Graph2",Graph2);

  // remove all the nodes and edges
  for (i = 0; i < NNodes; i++) {
    n = Graph->GetRndNId();
    Graph->DelNode(n);
  }

  PrintGStats("ManipulateNodesEdges:Graph",Graph);

  Graph1->Clr();
  PrintGStats("ManipulateNodesEdges:Graph1",Graph1);
}

//.........这里部分代码省略.........
    y = (long) (drand48() * NNodes);
    // Graph->GetEdges() is not correct for the loops (x == y),
    // skip the loops in this test
    if (x != y  &&  !Graph->IsEdge(x,y)) {
      n = Graph->AddEdge(x, y);
      NCount--;
    }
  }

  EXPECT_EQ(NEdges,Graph->GetEdges());

  EXPECT_EQ(0,Graph->Empty());
  EXPECT_EQ(1,Graph->IsOk());

  for (i = 0; i < NNodes; i++) {
    EXPECT_EQ(1,Graph->IsNode(i));
  }

  EXPECT_EQ(0,Graph->IsNode(NNodes));
  EXPECT_EQ(0,Graph->IsNode(NNodes+1));
  EXPECT_EQ(0,Graph->IsNode(2*NNodes));

  // nodes iterator
  NCount = 0;
  for (TNGraph::TNodeI NI = Graph->BegNI(); NI < Graph->EndNI(); NI++) {
    NCount++;
  }
  EXPECT_EQ(NNodes,NCount);

  // edges per node iterator
  NCount = 0;
  for (TNGraph::TNodeI NI = Graph->BegNI(); NI < Graph->EndNI(); NI++) {
    for (int e = 0; e < NI.GetOutDeg(); e++) {
      NCount++;
    }
  }
  EXPECT_EQ(NEdges,NCount);

  // edges iterator
  NCount = 0;
  for (TNGraph::TEdgeI EI = Graph->BegEI(); EI < Graph->EndEI(); EI++) {
    NCount++;
  }
  EXPECT_EQ(NEdges,NCount);

  // node degree
  for (TNGraph::TNodeI NI = Graph->BegNI(); NI < Graph->EndNI(); NI++) {
    Deg = NI.GetDeg();
    InDeg = NI.GetInDeg();
    OutDeg = NI.GetOutDeg();

    EXPECT_EQ(Deg,InDeg+OutDeg);
  }

  // assignment
  Graph1 = TNGraph::New();
  *Graph1 = *Graph;

  EXPECT_EQ(NNodes,Graph1->GetNodes());
  EXPECT_EQ(NEdges,Graph1->GetEdges());
  EXPECT_EQ(0,Graph1->Empty());
  EXPECT_EQ(1,Graph1->IsOk());

  // saving and loading
  {
    TFOut FOut(FName);
    Graph->Save(FOut);
    FOut.Flush();
  }

  {
    TFIn FIn(FName);
    Graph2 = TNGraph::Load(FIn);
  }

  EXPECT_EQ(NNodes,Graph2->GetNodes());
  EXPECT_EQ(NEdges,Graph2->GetEdges());
  EXPECT_EQ(0,Graph2->Empty());
  EXPECT_EQ(1,Graph2->IsOk());

  // remove all the nodes and edges
  for (i = 0; i < NNodes; i++) {
    n = Graph->GetRndNId();
    Graph->DelNode(n);
  }

  EXPECT_EQ(0,Graph->GetNodes());
  EXPECT_EQ(0,Graph->GetEdges());

  EXPECT_EQ(1,Graph->IsOk());
  EXPECT_EQ(1,Graph->Empty());

  Graph1->Clr();

  EXPECT_EQ(0,Graph1->GetNodes());
  EXPECT_EQ(0,Graph1->GetEdges());

  EXPECT_EQ(1,Graph1->IsOk());
  EXPECT_EQ(1,Graph1->Empty());
}

// Demos BFS functions on directed graph that is not fully connected
void DemoBFSDirectedRandom() {

  
  PNGraph G = TNGraph::New();
  
  TStr FName = TStr::Fmt("%s/sample_bfsdfs_ngraph.txt", DIRNAME);
  
  // Create benchmark graph, initially visually to confirm values are correct
  const int NNodes = 30;
  G = GenRndGnm<PNGraph>(NNodes, NNodes*2);
  // Add some more random edges
  for (int i = 0; i < 10; i++) {
    TInt Src, Dst;
    do {
      Src = G->GetRndNId();
      Dst = G->GetRndNId();
    }
    while (Src == Dst || G->IsEdge(Src, Dst));
    G->AddEdge(Src, Dst);
  }
  // Add isolated component
  G->AddNode(NNodes);
  G->AddNode(NNodes+1);
  G->AddNode(NNodes+2);
  G->AddEdge(NNodes, NNodes+1);
  G->AddEdge(NNodes+1, NNodes+2);
  G->AddEdge(NNodes+2, NNodes+1);
  printf("G->GetNodes() = %d, G->GetEdges() = %d\n", G->GetNodes(), G->GetEdges());
  
  
  //  SaveEdgeList(G, FName);
  
  //  G = LoadEdgeList<PNGraph>(FName);
  TIntStrH NodeLabelH;
  for (int i = 0; i < G->GetNodes(); i++) {
    NodeLabelH.AddDat(i, TStr::Fmt("%d", i));
  }
  DrawGViz(G, gvlDot, TStr::Fmt("%s/sample_bfsdfs_ngraph.png", DIRNAME), "Sample BFS Graph", NodeLabelH);
  
  printf("G->GetNodes() = %d, G->GetEdges() = %d\n", G->GetNodes(), G->GetEdges());
  
  TIntV NIdV;
  int StartNId, Hop, Nodes;
  
  //  for (int IsDir = 0; IsDir < 2; IsDir++) {
  int IsDir = 1;
  printf("IsDir = %d:\n", IsDir);
  
  StartNId = 11;
  Hop = 1;
  Nodes = GetNodesAtHop(G, StartNId, Hop, NIdV, IsDir);
  printf("Nodes = %d, GetNodesAtHop NIdV.Len() = %d\n", Nodes, NIdV.Len());
  for (int i = 0; i < NIdV.Len(); i++) {
    printf("NIdV[%d] = %d\n", i, NIdV[i].Val);
  }
  printf("Nodes == 2");
  printf("NIdV.Len() == 2");
  
  TIntPrV HopCntV;
  Nodes = GetNodesAtHops(G, StartNId, HopCntV, IsDir);
  printf("Nodes = %d, GetNodesAtHops HopCntV.Len() = %d\n", Nodes, HopCntV.Len());
  printf("Nodes == 10");
  printf("HopCntV.Len() == 10");
//  for (int N = 0; N < HopCntV.Len(); N++) {
//    printf("HopCntV[%d] = (%d, %d)\n", N, HopCntV[N].Val1.Val, HopCntV[N].Val2.Val);
//  }
  
  int Length, SrcNId, DstNId;
  SrcNId = 11;
  DstNId = G->GetNodes() - 1;
  
  Length = GetShortPath(G, SrcNId, DstNId, IsDir);
  printf("%d -> %d: SPL Length = %d\n", SrcNId, DstNId, Length);
  
  SrcNId = 11;
  DstNId = 27;
  Length = GetShortPath(G, SrcNId, DstNId, IsDir);
  printf("%d -> %d: SPL Length = %d\n", SrcNId, DstNId, Length);
  
  TIntH NIdToDistH;
  int MaxDist = 9;
  Length = GetShortPath(G, SrcNId, NIdToDistH, IsDir, MaxDist);
//  for (int i = 0; i < min(5,NIdToDistH.Len()); i++) {
//    printf("NIdToDistH[%d] = %d\n", i, NIdToDistH[i].Val);
//  }
  
  TInt::Rnd.PutSeed(0);
  
  int FullDiam;
  double EffDiam, AvgSPL;
  int NTestNodes = G->GetNodes() / 2;
  
  FullDiam = GetBfsFullDiam(G, NTestNodes, IsDir);
  printf("FullDiam = %d\n", FullDiam);
  
  EffDiam = GetBfsEffDiam(G, NTestNodes, IsDir);
  printf("EffDiam = %.3f\n", EffDiam);
  
  EffDiam = GetBfsEffDiam(G, NTestNodes, IsDir, EffDiam, FullDiam);
//.........这里部分代码省略.........