com/example/portfolio3/EdgeGraph.java



package com.example.portfolio3;

// origin: <https://moodle.ruc.dk/course/section.php?id=211877>

/// EdgeGraph - One big set of all edges in the graph
class EdgeGraph extends AbstractGraph {

  /// foo
  EdgeGraph() {}

  /// foo
  Set<Edge> edges=new HashSet<>();

  /// foo
  public void insertEdge(Vertex v1,Vertex v2,int w){
    edges.add(new Edge(v1,v2,w));
  }

  /// foo
  public Collection<Edge> edges(){return edges;}

  /// foo
  public Collection<Edge> outEdge(Vertex v){
    ArrayList<Edge> outEdge=new ArrayList<>();
    for(Edge e:edges)if(e.from()==v)outEdge.add(e);
    return outEdge;
  }

  /// foo
  public Integer getWeight(Vertex v1,Vertex v2){
    // linear in number of edges in the graph
    for(Edge e:edges){
      if(e.from()==v1 && e.to()==v2)return e.weight();
    }
    return null;
  }
}