comparablepairuos.java

来自「国外的数据结构与算法分析用书」· Java 代码 · 共 27 行

package dslib.base;

/**	A descendant of PairUos which defines comparison for two pairs whereby the
	first items are compared first, and if they are equal, the second items are
	compared. */
public class ComparablePairUos extends PairUos implements Comparable
{
	/**	Constructor of the class 
		Analysis: Time = O(1) */
	public ComparablePairUos(Object o1, Object o2)
	{
		super(o1, o2);
	}
	
	/**	Redefine compareTo method by comparing the key values
		Analysis: Time = O(1) */
	public int compareTo(Object other)
	{
		Comparable first = (Comparable)((ComparablePairUos)other).firstItem();
		Comparable second = (Comparable)((ComparablePairUos)other).secondItem();
		if(((Comparable)firstItem()).compareTo(first) == 0)
			return ((Comparable)secondItem()).compareTo(second);
		else
			return ((Comparable)firstItem()).compareTo(first);
	}	
}