public class Triangolo implements Poligono
{
   private int a;
   private int b;
   private int c;
   
   public Triangolo(int p, int q, int r)
   {
      int pTmp = p;
      int qTmp = q;
      int rTmp = r;
      
      // ordinamento per selezione
      if (pTmp < qTmp)
      {
         int tmp = pTmp;
         pTmp = qTmp;
         qTmp = tmp;
      }
      if (pTmp < rTmp)
      {
         int tmp = pTmp;
         pTmp = rTmp;
         rTmp = tmp;
      }
      if (qTmp < rTmp)
      {
         int tmp = qTmp;
         qTmp = rTmp;
         rTmp = tmp;
      }
      
      if (pTmp > qTmp + rTmp)
         throw new IllegalArgumentException();

      a = p;
      b = q;
      c = r;
   }
   
   public int perimetro() { return a + b + c; }
   
   public double area()
   {
      double p = perimetro() / 2;
      return Math.sqrt(p * (p - a) * (p - b) * (p - c));
   }
   
   public int compareTo(Object obj)
   {
      Poligono p = (Poligono) obj;
      if ( area() - p.area() < 0)
         return -1;
      else if ( area() - p.area() > 0)
         return +1;
      else return 0;
   }
   
   public String toString()
   {
      return "<T>: " + a + ", " + b + ", " + c;
   }
}