Bikeshedding

gistfile1.txt

abstract class Person implements Comparable<Person> {
    protected String lastName, firstName;

    public Person(String lastName, String firstName) {
        this.lastName = lastName;
        this.firstName = firstName;
    }

    public String fullName() { return firstName+" "+lastName; }

    protected abstract int rank();

    public compareTo(Person o) {
        int r1 = this.rank(), r2 = o.rank();
        return r1 != r2 ? r1-r2 : this.fullName().compareTo(o.fullName());
    }
}

class Instructor extends Person {
    protected int rank() { return 5; }
}

class TeachingAssistant extends Person {
    protected int rank() { return 10; }
}

class Student extends Person {
    protected int rank() { return 15; }
}

gistfile2.txt

abstract class Person implements Comparable<Person> {
    protected String lastName, firstName;

    public Person(String lastName, String firstName) {
        this.lastName = lastName;
        this.firstName = firstName;
    }

    public String fullName() { return firstName+" "+lastName; }

    public compareTo(Person o) {
        if (this.getClass() == o.getClass()) {
           return this.fullName().compareTo(o.fullName());
        } else if (this instanceof Instructor && (o instanceof TeachingAssistant || o instanceof Student)) {
           return 1;
        } else if (this instanceof TeachingAssistant && o instanceof Student) {
           return 1;
        }
        return -1;
    }
}

class Instructor extends Person {
}

class TeachingAssistant extends Person {
}

class Student extends Person {
}

gistfile3.txt

abstract class Person implements Comparable<Person> {
    protected String lastName, firstName;

    public Person(String lastName, String firstName) {
        this.lastName = lastName;
        this.firstName = firstName;
    }

    public String fullName() { return firstName+" "+lastName; }

    public compareTo(Person o) {
        return this.fullName().compareTo(o);
    }
}

class Instructor extends Person {
    public int compareTo(Person o) {
        if (o instanceof TeachingAssistant || o instanceof Student) {
           return 1;
        }
        return super.compareTo(o);
    }
}

class TeachingAssistant extends Person {
    public int compareTo(Person o) {
        if (o instanceof Instructor) { 
           return -1; 
        } if (o instanceof Student) {
           return 1;
        }
        return super.compareTo(o);
    }
}

class Student extends Person {
    public int compareTo(Person o) {
        if (o instanceof Instructor || o instanceof TeachingAssistant) { 
           return -1;
        }
        return super.compareTo(o);
    }
}

gistfile4.txt

abstract class Person implements Comparable<Person> {
    protected String lastName, firstName;

    public Person(String lastName, String firstName) {
        this.lastName = lastName;
        this.firstName = firstName;
    }

    public String fullName() { return firstName+" "+lastName; }

    public compareTo(Person o) {
        return this.fullName().compareTo(o);
    }
}

class Instructor extends Person {
}

class TeachingAssistant extends Person {
}

class Student extends Person {
}

class Main {
    public static void main(String[] args) {
        Comparator<Person> cmp = new Comparator<Person>() {
            public compare(Person a, Person b) {
                if (a.getClass() == b.getClass()) {
                   return a.compareTo(b);
                } else if (a instanceof Instructor && (b instanceof TeachingAssistant || b instanceof Student)) {
                   return 1;
                } else if (a instanceof TeachingAssistant && b instanceof Student) {
                   return 1;
                }
                return -1;
            }
        };
    }
}