# BoostBreadthFirstSearchTree

VTKExamples/Cxx/Graphs/BoostBreadthFirstSearchTree

### Code

BoostBreadthFirstSearchTree.cxx

    #include <vtkSmartPointer.h>

    #include <vtkBoostBreadthFirstSearchTree.h>
    #include <vtkDataSetAttributes.h>
    #include <vtkDoubleArray.h>
    #include <vtkGraphLayoutView.h>
    #include <vtkIntArray.h>
    #include <vtkMutableUndirectedGraph.h>
    #include <vtkRenderWindowInteractor.h>
    #include <vtkTree.h>

    int main(int, char *[])
    {
      vtkSmartPointer<vtkMutableUndirectedGraph> g =
        vtkSmartPointer<vtkMutableUndirectedGraph>::New();

      // Create 5 vertices
      vtkIdType v1 = g->AddVertex();
      vtkIdType v2 = g->AddVertex();
      vtkIdType v3 = g->AddVertex();
      vtkIdType v4 = g->AddVertex();
      vtkIdType v5 = g->AddVertex();

      // Create a graph
      g->AddEdge(v1, v2);
      g->AddEdge(v1, v3);
      g->AddEdge(v2, v4);
      g->AddEdge(v4, v5);

      vtkSmartPointer<vtkBoostBreadthFirstSearchTree> bfsTree =
        vtkSmartPointer<vtkBoostBreadthFirstSearchTree>::New();
      bfsTree->SetOriginVertex(v5);
      bfsTree->SetInput(g);
      bfsTree->Update();

      {
      // Original graph
      vtkSmartPointer<vtkGraphLayoutView> graphLayoutView =
        vtkSmartPointer<vtkGraphLayoutView>::New();
      graphLayoutView->AddRepresentationFromInput(g);
      graphLayoutView->SetLayoutStrategyToTree();
      graphLayoutView->ResetCamera();
      graphLayoutView->Render();
      graphLayoutView->GetInteractor()->Start();
      }

      {
      // BFS tree
      vtkSmartPointer<vtkGraphLayoutView> graphLayoutView =
        vtkSmartPointer<vtkGraphLayoutView>::New();
      graphLayoutView->SetLayoutStrategyToTree();
      graphLayoutView->AddRepresentationFromInput(bfsTree->GetOutput());
      graphLayoutView->ResetCamera();
      graphLayoutView->Render();
      graphLayoutView->GetInteractor()->Start();
      }

      return EXIT_SUCCESS;
    }

### CMakeLists.txt

    cmake_minimum_required(VERSION 2.8)

    PROJECT(BoostBreadthFirstSearchTree)

    find_package(VTK REQUIRED)
    include(${VTK_USE_FILE})

    add_executable(BoostBreadthFirstSearchTree MACOSX_BUNDLE BoostBreadthFirstSearchTree.cxx )

    target_link_libraries(BoostBreadthFirstSearchTree ${VTK_LIBRARIES})

### Download and Build BoostBreadthFirstSearchTree

Click here to download BoostBreadthFirstSearchTree and its CMakeLists.txt file. Once the tarball BoostBreadthFirstSearchTree.tar has been downloaded and extracted,

    cd BoostBreadthFirstSearchTree/build

If VTK is installed:

    cmake ..

If VTK is not installed but compiled on your system, you will need to specify the path to your VTK build:

    cmake -DVTK_DIR:PATH=/home/me/vtk_build ..

Build the project:

    make

and run it:

    ./BoostBreadthFirstSearchTree

WINDOWS USERS PLEASE NOTE: Be sure to add the VTK bin directory to your path. This will resolve the VTK dll's at run time.