interface Graph { // Graph class ADT
  // Initialize the graph with some number of vertices
  void init(int n);

  // Return the number of vertices
  int nodeCount();

  // Return the current number of edges
  int edgeCount();

  // Get the value of node with index v
  Object getValue(int v);

  // Set the value of node with index v
  void setValue(int v, Object val);
  
  // Adds a new edge from node v to node w with weight wgt
  void addEdge(int v, int w, int wgt);

  // Get the weight value for an edge
  int weight(int v, int w);

  // Removes the edge from the graph.
  void removeEdge(int v, int w);

  // Returns true iff the graph has the edge
  boolean hasEdge(int v, int w);

  // Returns an array containing the indicies of the neighbors of v
  int[] neighbors(int v);
}