content: /*************************************************************************
   *  Compilation:  javac EdgeWeightedDigraph.java
   *  Execution:    java EdgeWeightedDigraph V E
   *  Dependencies: Bag.java DirectedEdge.java
   *
   *  An edge-weighted digraph, implemented using adjacency lists.
   *
   *************************************************************************/
  
  /**
   *  The <tt>EdgeWeightedDigraph</tt> class represents an directed graph of vertices
   *  named 0 through V-1, where each edge has a real-valued weight.
   *  It supports the following operations: add an edge to the graph,
   *  iterate over all of edges leaving a vertex.
   *  Parallel edges and self-loops are permitted.
   *  <p>
   *  For additional documentation, see <a href="http://algs4.cs.princeton.edu/44sp">Section 4.4</a> of
   *  <i>Algorithms, 4th Edition</i> by Robert Sedgewick and Kevin Wayne.
   */
  
  
  
  public class EdgeWeightedDigraph {
      private final int V;
      private int E;
      private Bag<DirectedEdge>[] adj;
      
      /**
       * Create an empty edge-weighted digraph with V vertices.
       */
      public EdgeWeightedDigraph(int V) {
          if (V < 0) throw new RuntimeException("Number of vertices must be nonnegative");
          this.V = V;
          this.E = 0;
          adj = (Bag<DirectedEdge>[]) new Bag[V];
          for (int v = 0; v < V; v++)
              adj[v] = new Bag<DirectedEdge>();
      }
  
     /**
       * Create a edge-weighted digraph with V vertices and E edges.
       */
      public EdgeWeightedDigraph(int V, int E) {
          this(V);
          if (E < 0) throw new RuntimeException("Number of edges must be nonnegative");
          for (int i = 0; i < E; i++) {
              int v = (int) (Math.random() * V);
              int w = (int) (Math.random() * V);
              double weight = Math.round(100 * Math.random()) / 100.0;
              DirectedEdge e = new DirectedEdge(v, w, weight);
              addEdge(e);
          }
      }
  
      /**
       * Create an edge-weighted digraph from input stream.
       */
      public EdgeWeightedDigraph(In in) {
          this(in.readInt());
          int E = in.readInt();
          for (int i = 0; i < E; i++) {
              int v = in.readInt();
              int w = in.readInt();
              double weight = in.readDouble();
              addEdge(new DirectedEdge(v, w, weight));
          }
      }
  
     /**
       * Copy constructor.
       */
      public EdgeWeightedDigraph(EdgeWeightedDigraph G) {
          this(G.V());
          this.E = G.E();
          for (int v = 0; v < G.V(); v++) {
              // reverse so that adjacency list is in same order as original
              Stack<DirectedEdge> reverse = new Stack<DirectedEdge>();
              for (DirectedEdge e : G.adj[v]) {
                  reverse.push(e);
              }
              for (DirectedEdge e : reverse) {
                  adj[v].add(e);
              }
          }
      }
  
     /**
       * Return the number of vertices in this digraph.
       */
      public int V() {
          return V;
      }
  
     /**
       * Return the number of edges in this digraph.
       */
      public int E() {
          return E;
      }
  
  
     /**
       * Add the edge e to this digraph.
       */
      public void addEdge(DirectedEdge e) {
          int v = e.from();
          adj[v].add(e);
          E++;
      }
  
  
     /**
       * Return the edges leaving vertex v as an Iterable.
       * To iterate over the edges leaving vertex v, use foreach notation:
       * <tt>for (DirectedEdge e : graph.adj(v))</tt>.
       */
      public Iterable<DirectedEdge> adj(int v) {
          return adj[v];
      }
  
     /**
       * Return all edges in this graph as an Iterable.
       * To iterate over the edges, use foreach notation:
       * <tt>for (DirectedEdge e : graph.edges())</tt>.
       */
      public Iterable<DirectedEdge> edges() {
          Bag<DirectedEdge> list = new Bag<DirectedEdge>();
          for (int v = 0; v < V; v++) {
              for (DirectedEdge e : adj(v)) {
                  list.add(e);
              }
          }
          return list;
      } 
  
     /**
       * Return number of edges leaving v.
       */
      public int outdegree(int v) {
          return adj[v].size();
      }
  
  
  
     /**
       * Return a string representation of this graph.
       */
      public String toString() {
          String NEWLINE = System.getProperty("line.separator");
          StringBuilder s = new StringBuilder();
          s.append(V + " " + E + NEWLINE);
          for (int v = 0; v < V; v++) {
              s.append(v + ": ");
              for (DirectedEdge e : adj[v]) {
                  s.append(e + "  ");
              }
              s.append(NEWLINE);
          }
          return s.toString();
      }
  
      /**
       * Test client.
       */
      public static void main(String[] args) {
          In in = new In(args[0]);
          EdgeWeightedDigraph G = new EdgeWeightedDigraph(in);
          StdOut.println(G);
      }
  
  }
  