//
// FINALLY, a correct, modular, and extensible solution
//
// plus it supplies a reasonable hashCode() implementation
// along the guidelines of chapter 3 of "Effective Java"
// 

class A { 
  public int a;
  public A(int i) { a = i;}
  public boolean equals(Object o) {
    if (o == null) return false;
    if (this == o) return true;
    return ((this.getClass() == o.getClass()) &&
	    (a == ((A) o).a));
  }
  public int hashCode() {
    return 17 + a;
  }
}

class B extends A { 
  public int b;
  public B(int i, int j) {super(i); b = j;}
  public boolean equals(Object o) {
    if (o == null) return false;
    if (this == o) return true;
    return ((this.getClass() == o.getClass()) &&
	    (b == ((B) o).b) &&
	    (super.equals(o)));
  }
  public int hashCode() {
    return b + 37*super.hashCode();
  }
}

class C extends B { 
  public int c;
  public C(int i, int j, int k) {super(i,j); c = k;}
  public boolean equals(Object o) {
    if (o == null) return false;
    if (this == o) return true;
    return ((this.getClass() == o.getClass()) &&
	    (c == ((C) o).c) &&
	    (super.equals(o)));
  }
  public int hashCode() {
    return c + 37*super.hashCode();
  }
}

public class EqualsTest6 {
    public static void main(String[] args) {
	A a1 = new A(1);
	B b1 = new B(1,1);
	C c1 = new C(1,1,1);
	
	System.out.println("a1.equals(b1) = " + a1.equals(b1));
	System.out.println("a1.equals(c1) = " + a1.equals(c1));
	System.out.println("b1.equals(a1) = " + b1.equals(a1));
	System.out.println("b1.equals(c1) = " + b1.equals(c1));
	System.out.println("c1.equals(a1) = " + c1.equals(a1));
	System.out.println("c1.equals(b1) = " + c1.equals(b1));

	System.out.println("a1.equals(a1) = " + a1.equals(a1));
	System.out.println("b1.equals(b1) = " + b1.equals(b1));
	System.out.println("c1.equals(c1) = " + c1.equals(c1));

	System.out.println("a1.equals(new A(1)) = " + a1.equals(new A(1)));
	System.out.println("b1.equals(new B(1,1)) = " + b1.equals(new B(1,1)));
	System.out.println("c1.equals(new C(1,1,1)) = " + c1.equals(new C(1,1,1)));
	System.out.println("c1.equals(null) = " + c1.equals(null));
	System.out.println("a1.hashCode() = " + a1.hashCode());
	System.out.println("(new A(1)).hashCode() = " + (new A(1)).hashCode());
	System.out.println("b1.hashCode() = " + b1.hashCode());
	System.out.println("(new B(1,1)).hashCode() = " + (new B(1,1)).hashCode());
	System.out.println("c1.hashCode() = " + c1.hashCode());
	System.out.println("(new C(1,1,1)).hashCode() = " + (new C(1,1,1)).hashCode());

    }
}