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package algs44;
import stdlib.*;
/* ***********************************************************************
 *  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) {
    StdIn.fromFile ("data/jobsPC.txt");

    // 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.format("%4d %7.1f %7.1f\n", i, lp.distTo(i), lp.distTo(i+N));
    }
    StdOut.format("Finish time: %7.1f\n", lp.distTo(sink));
  }

}