[OOP] Common Type System - Задача 1,2,3

using System;
using System.Text;

public enum University
{
    SU, TU, NBU, UNSS
}

public enum Faculty
{
    Philosophy, Law, Mathematics, Phisics, Business, Management, Telecommunications
}

public enum Specialty
{
    Telecommunications, Marketing, Business, Entrepreneurship, Phisics, Mathematics, Informatics, Law, Philosophy
}

public class Student : ICloneable, IComparable<Student>
{
    private string firstName;
    private string middleName;
    private string lastName;
    private string address;
    private int phone;
    private int course;
    private int ssn;
    private Specialty specialty;
    private University university;
    private Faculty faculty;

    public string FirstName
    {
        get { return this.firstName; }
        set { this.firstName = value; }
    }
    public string MiddleName
    {
        get { return this.middleName; }
        set { this.middleName = value; }
    }
    public string LastName
    {
        get { return this.lastName; }
        set { this.lastName = value; }
    }
    public string Address
    {
        get { return this.address; }
        set { this.address = value; }
    }
    public int Phone
    {
        get { return this.phone; }
        set { this.phone = value; }
    }
    public int Course
    {
        get { return this.course; }
        set { this.course = value; }
    }
    public Specialty Specialty
    {
        get { return this.specialty; }
        set { this.specialty = value; }
    }
    public University University
    {
        get { return this.university; }
        set { this.university = value; }
    }
    public Faculty Faculty
    {
        get { return this.faculty; }
        set { this.faculty = value; }
    }
    public int SSN
    {
        get { return this.ssn; }
        set { this.ssn = value; }
    }
    public Student()
    {
    }
    public Student(string firstName, string middleName, string lastName, string address, int phone, int course, int ssn, Specialty specialty, University university, Faculty faculty)
    {
        this.FirstName = firstName;
        this.MiddleName = middleName;
        this.LastName = lastName;
        this.Address = address;
        this.Phone = phone;
        this.Course = course;
        this.SSN = ssn;
        this.Specialty = specialty;
        this.University = university;
        this.Faculty = faculty;
    }
    public override string ToString()
    {
        StringBuilder build = new StringBuilder();
        build.AppendLine(this.FirstName);
        build.AppendLine(this.MiddleName);
        build.AppendLine(this.LastName);
        build.AppendLine(this.Address);
        build.AppendLine(this.Phone.ToString());
        build.AppendLine(this.Course.ToString());
        build.AppendLine(this.SSN.ToString());
        build.AppendLine(this.Specialty.ToString());
        build.AppendLine(this.University.ToString());
        build.AppendLine(this.Faculty.ToString());

        return build.ToString();
    }

    public override bool Equals(object param)
    {
        Student student = param as Student;

        if (student == null)
        {
            return false;
        }

        if (!Object.Equals(this.FirstName, student.FirstName))
        {
            return false;
        }

        if (!Object.Equals(this.LastName, student.LastName))
        {
            return false;
        }
        if (this.SSN != student.SSN)
        {
            return false;
        }

        return true;
    }

    public static bool operator ==(Student student1, Student student2)
    {
        return Student.Equals(student1, student2);
    }

    public static bool operator !=(Student student1, Student student2)
    {
        return !(Student.Equals(student1, student2));
    }

    public override int GetHashCode()
    {
        return LastName.GetHashCode() ^ SSN.GetHashCode();
    }
    public Student Clone()
    {
        Student clone = new Student
            (
            this.FirstName,
            this.MiddleName,
            this.LastName,
            this.Address,
            this.Phone,
            this.Course,
            this.SSN,
            this.Specialty,
            this.University,
            this.Faculty
            );
        return clone;
    }

    object ICloneable.Clone()
    {
        return this.Clone();
    }

    public int CompareTo(Student student)
    {
        if (this.LastName != student.LastName)
        {
            return (String.Compare(this.LastName, student.LastName));
        }
        if (this.FirstName != student.FirstName)
        {
            return (String.Compare(this.FirstName, student.FirstName));
        }
        if (this.SSN != student.SSN)
        {
            return ( this.SSN - student.SSN);
        }
        return 0;
    }
}