/**
*************************************************
  Skrá: T203Sd4_3.cs
  Höfundur: Ragnar Geir Brynjólfsson.
  Dagsetning: 02.06.2005.
  Sýnidæmi um útfærslu mengis.
*************************************************
*/
using System;
using System.Collections;

class MyStringSet : ArrayList  {
  public MyStringSet():base() {
  }
  public void union (MyStringSet m) {
    foreach(String s in m)
       this.myadd(s);
  }
  public MyStringSet intersect(MyStringSet m) {
    MyStringSet temp = new MyStringSet();
    foreach(String s in m)
      if(this.contains(s))
        temp.myadd(s);
      return temp;
  }
  public void subtract(MyStringSet m) {
    foreach(String s in  m)
      this.myremove(s);
  }
  public void myadd(String s) {
    if (!this.Contains(s))
      base.Add(s);
  }
  public void myremove(String s) {
    base.Remove(s);
  }
  public bool contains(String s) {
    return base.Contains(s);
  }
  public int size() {
    return base.Count;
  }
  public bool isEmpty(){
    return this.size()==0;  
  }
  public override String ToString() {
    String utstr="[ ";
    foreach(String s in this)
      utstr+=s+" ";
    utstr+="]";
    return utstr;
  }
}

class T203Sd4_3 {
  static void Main() {
    MyStringSet Sundlaug = new MyStringSet();
    MyStringSet Heiti_p = new MyStringSet();
    Sundlaug.myadd("Anna");
    Sundlaug.myadd("Jói");
    Heiti_p.myadd("Sigga");
    Heiti_p.myadd("Kalli");
    Console.WriteLine("Í lauginni: "+Sundlaug.ToString());
    Console.WriteLine("Í heita pottinum: "+Heiti_p);
    Sundlaug.union(Heiti_p);
    Console.WriteLine("Í potti og laug eru: " + Sundlaug.ToString());
    Sundlaug.subtract(Heiti_p);
    Console.WriteLine("Laugin ein: " + Sundlaug.ToString());
    Sundlaug.myadd("Sigga");
    Console.WriteLine("Sigga er bæði í laug og potti:" + Sundlaug.ToString());
    MyStringSet snid = Sundlaug.intersect(Heiti_p);
    Console.WriteLine("Bæði í potti og laug: " + snid.ToString());
    Sundlaug.myadd("Hannes");
    Console.WriteLine("Hannes kemur í laugina: " + Sundlaug.ToString());
  }
}