Exemple #1
0
vector<Component> FindZeroIndegreeComponents(const DirectedGraph &graph) {
  vector<Component> components = FindWeaklyConnectedComponents(graph);
  vector<bool> top_component_flags(components.size(), true);
  vector<int> vertices_components(graph.size());
  for (int component_number = 0; 
       component_number < components.size(); ++component_number) {
    for (int vertex : components[component_number]) {
      vertices_components[vertex] = component_number;
    }
  }
  for (int vertex = 0; vertex < graph.size(); ++vertex) {
    for (int adj_vertex : graph.GetAdjacentVertices(vertex)) {
      if (vertices_components[vertex] != vertices_components[adj_vertex]) {
        top_component_flags[vertices_components[adj_vertex]] = false;
      }
    }
  }
  vector<Component> top_components;
  for (int component_number = 0; 
       component_number < components.size(); ++component_number) {
    if (top_component_flags[component_number]) {
      top_components.push_back(components[component_number]);
    }
  }
  return top_components;
}
Exemple #2
0
DirectedGraph Transpose(const DirectedGraph &graph) {
  DirectedGraph tr_graph = DirectedGraph(graph.size());
  for (int vertex = 0; vertex < graph.size(); ++vertex) {
    for (int adj_vertex : graph.GetAdjacentVertices(vertex)) {
      tr_graph.AddEdge(Edge(adj_vertex, vertex));
    }
  }
  return tr_graph;
}
Exemple #3
0
void DepthFirstSearch(const DirectedGraph &graph, vector<int> &order, 
         vector<bool> &visited, int vertex) {
  visited[vertex] = true;
  for (int outgoing_vertex : graph.GetAdjacentVertices(vertex)) {
    if (!visited[outgoing_vertex]) {
      DepthFirstSearch(graph, order, visited, outgoing_vertex);
    }
  }
  order.push_back(vertex);
}