structure
Class ComparableAssociation<K extends java.lang.Comparable<K>,V>

java.lang.Object
  structure.Association<K,V>
      structure.ComparableAssociation<K,V>

All Implemented Interfaces:

java.lang.Comparable<ComparableAssociation<K,V>>, java.util.Map.Entry<K,V>

public class ComparableAssociation<K extends java.lang.Comparable<K>,V>
extends Association<K,V>
implements java.lang.Comparable<ComparableAssociation<K,V>>, java.util.Map.Entry<K,V>

A class implementing a comparable key-value pair. This class associates an immutable key with a mutable value. Useful for many other structures. Example usage:

To print out a list of professors sorted by the number of classes a particular student took from each, we could use the following:

 public static void main(String[] argv){
        //initialize a new fib heap
        FibHeap classesTaken = new FibHeap();

        //add professors and classes taken to a heap
        classesTaken.add(new ComparableAssociation(new Integer(5), "Andrea"));
        classesTaken.add(new ComparableAssociation(new Integer(1), "Barbara"));
        classesTaken.add(new ComparableAssociation(new Integer(3), "Bill"));
        classesTaken.add(new ComparableAssociation(new Integer(2), "Duane"));   
        classesTaken.add(new ComparableAssociation(new Integer(1), "Tom"));     

        //print out classes taken
        while(!classesTaken.isEmpty()){
            ComparableAssociation p = (ComparableAssociation)classesTaken.remove();
            System.out.println(p.getValue() + " is " + p.getKey() + " years old.");
        }
 }
 

Constructor Summary

ComparableAssociation(K key)
Construct an association that can be ordered, from only a key.

ComparableAssociation(K key, V value)
Construct a key-value association that can be ordered.

Method Summary

int	compareTo(ComparableAssociation<K,V> that) Determine the order of two comparable associations, based on key.
java.lang.String	toString() Construct a string representation of the ComparableAssociation.

Methods inherited from class structure.Association

equals, getKey, getValue, hashCode, setValue

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Map.Entry

equals, getKey, getValue, hashCode, setValue

Constructor Detail

ComparableAssociation

public ComparableAssociation(K key)

Construct an association that can be ordered, from only a key. The value is set to null.

Parameters:

key - The (comparable) key.

Pre:

key is non-null

Post:

constructs comparable association with null value

ComparableAssociation

public ComparableAssociation(K key,
                             V value)

Construct a key-value association that can be ordered.

Parameters:

key - The (comparable) key.

value - The (possibly comparable) associated value.

Pre:

key is non-null

Post:

constructs association between a comparable key and a value

Method Detail

compareTo

public int compareTo(ComparableAssociation<K,V> that)

Determine the order of two comparable associations, based on key.

Specified by:

compareTo in interface java.lang.Comparable<ComparableAssociation<K extends java.lang.Comparable<K>,V>>

Parameters:

other - The other comparable association.

Returns:

Value less-than equal to or greater than zero based on comparison

Pre:

other is non-null ComparableAssociation

Post:

returns integer representing relation between values

toString

public java.lang.String toString()

Construct a string representation of the ComparableAssociation.

Overrides:

toString in class Association<K extends java.lang.Comparable<K>,V>

Returns:

The string representing the ComparableAssociation.

Post:

returns string representation