content: /*************************************************************************
   *  Compilation:  javac CPM.java
   *  Execution:    java CPM < input.txt
   *  Dependencies: EdgeWeightedDigraph.java AcyclicDigraphLP.java StdOut.java
   *  Data files:   http://algs4.cs.princeton.edu/44sp/jobsPC.txt
   *
   *  Critical path method.
   *
   *  % java CPM < jobsPC.txt
   *   job   start  finish
   *  --------------------
   *     0     0.0    41.0
   *     1    41.0    92.0
   *     2   123.0   173.0
   *     3    91.0   127.0
   *     4    70.0   108.0
   *     5     0.0    45.0
   *     6    70.0    91.0
   *     7    41.0    73.0
   *     8    91.0   123.0
   *     9    41.0    70.0
   *  Finish time:   173.0
   *
   *************************************************************************/
  
  public class CPM {
  
      public static void main(String[] args) {
  
          // number of jobs
          int N = StdIn.readInt();
  
          // source and sink
          int source = 2*N;
          int sink   = 2*N + 1;
  
          // build network
          EdgeWeightedDigraph G = new EdgeWeightedDigraph(2*N + 2);
          for (int i = 0; i < N; i++) {
              double duration = StdIn.readDouble();
              G.addEdge(new DirectedEdge(source, i, 0.0));
              G.addEdge(new DirectedEdge(i+N, sink, 0.0));
              G.addEdge(new DirectedEdge(i, i+N,    duration));
  
              // precedence constraints
              int M = StdIn.readInt();
              for (int j = 0; j < M; j++) {
                  int precedent = StdIn.readInt();
                  G.addEdge(new DirectedEdge(N+i, precedent, 0.0));
              }
          }
  
          // compute longest path
          AcyclicLP lp = new AcyclicLP(G, source);
  
          // print results
          StdOut.println(" job   start  finish");
          StdOut.println("--------------------");
          for (int i = 0; i < N; i++) {
              StdOut.printf("%4d %7.1f %7.1f\n", i, lp.distTo(i), lp.distTo(i+N));
          }
          StdOut.printf("Finish time: %7.1f\n", lp.distTo(sink));
      }
  
  }
  