//QuadraticComparator.java

//what does sorting do to Quadratics?
	//Collections.sort(myQuadraticList);    //***runtime error.  
	//***there is no "natural ordering" for user-defined classes. 
	//***must specify how quadratic objects are compared with a Comparator.

//enables:	Collections.sort(collectionObject,new QuadraticComparator());     

import java.util.*;

public class QuadraticComparator implements Comparator {

    //implementing the Comparator interface requires the compare method
    //return 0 if equal, positive if a>b, negative if a<b

    //compare by a, then by b, then by c.  meaningful???
    public int compare(Object a, Object b) {
	//cast the Object parameters to Quadratics:
	Quadratic q1 = (Quadratic) a;
	Quadratic q2 = (Quadratic) b;

	if (q1.getA() > q2.getA())
	    return 1;
	else if (q1.getA() < q2.getA())
	    return -1;
	else if (q1.getB() > q2.getB())
		 return 1;
	else if (q1.getB() < q2.getB())
	    return -1;
	else if (q1.getC() > q2.getC())
		 return 1;
	else if (q1.getC() < q2.getC())
		 return -1;
	else 
	    return 0;
    }
}