doubleandedgesortedondouble.java

经典的货郎担问题解决办法

/*
** This code was written by Kent Paul Dolan.  See accompanying file
** TravellerDoc.html for status for your use.
*/

package com.well.www.user.xanthian.java.structures;

public class DoubleAndEdgeSortedOnDouble
  implements ContentComparable
{
  private double m_double;
  private Edge m_edge;

  public DoubleAndEdgeSortedOnDouble( double p_double, Edge p_edge )
  {
    super();
    m_double = p_double;
    m_edge = p_edge;
  }

  public DoubleAndEdgeSortedOnDouble( DoubleAndEdgeSortedOnDouble that )
  {
    this( that.m_double, that.m_edge );
  }

  public double getDouble()
  {
    return m_double;
  }

  public Edge getEdge()
  {
    return m_edge;
  }

  public String toString()
  {
    return new String
    (
      "("
      + this.m_double
      + ","
      + this.m_edge.toString()
      + ")"
    );
  }

  public int compareTo( Object that )
  {

/*
** We cannot even afford the cost of an if (DB) in a loop this hot, so
** comment out the debugging stuff.
*/

    if
    (
      this.m_double < ( ( DoubleAndEdgeSortedOnDouble ) that).m_double
    )
    {
      return Sortable.THIS_LESS_THAN;
    }

    if
    (
      this.m_double > ( ( DoubleAndEdgeSortedOnDouble ) that).m_double
    )
    {
      return Sortable.THIS_GREATER_THAN;
    }

    return Sortable.THIS_EQUAL_TO;

  }

  public void swap ( Object l, Object r )
  {

    // rename for ease of use
    DoubleAndEdgeSortedOnDouble left = ( DoubleAndEdgeSortedOnDouble ) l;

    // rename for ease of use
    DoubleAndEdgeSortedOnDouble right = ( DoubleAndEdgeSortedOnDouble ) r;

    double doubleTemp;

    doubleTemp = left.m_double;
    left.m_double = right.m_double;
    right.m_double = doubleTemp;

    // Edges already have a swap routine, might as well use it.

    left.m_edge.swap( (Object) left.m_edge, (Object) right.m_edge);

/*
** We cannot even afford the cost of an if (DB) in a loop this hot, so
** comment out the debugging stuff.
*/

//      System.out.println
//      (
//        "Swapped " + left.toString() + " with " + right.toString()
//      );

  }

  public boolean contentIsTheSameAs( Object that )
  {
    return
      (
        (
          this.m_edge.contentIsTheSameAs( ( (DoubleAndEdgeSortedOnDouble) that ).getEdge() )
        )
        &&
        (
          this.m_double
          ==
          ( (DoubleAndEdgeSortedOnDouble) that ).getDouble()
        )
      );
  }

}