[JAVA] Klasy Figura

/////////////////////////Figura.java/////////////////////////////////


package figura;

public abstract class Figura {

    public abstract String KlasaFigury();
    public abstract double PolePowierzchni();
    public abstract double Obwod();

    public static void main(String[] args) {

            Figura[] figures = new Figura[30];
            Grupa group = new Grupa(30);
            Okrag[] circles = new Okrag[10];
            Prostokat[] rectangles = new Prostokat[10];
            Trojkat[] triangles = new Trojkat[10];
            for (int i = 0; i < 10; ++i) {
                circles[i] = new Okrag(i);
                figures[i] = circles[i];
            }
            for (int i = 10; i < 20; ++i) {
                rectangles[i-10] = new Prostokat(i, i);
                figures[i] = rectangles[i-10];
            }
            for (int i = 20; i < 30; ++i) {
                triangles[i-20] = new Trojkat(i, i, i);
                figures[i] = triangles[i-20];
            }

            for (int i = 0; i < 30; ++ i) {
                group.UstawFigure(i, figures[i]);
            }

            group.Wyswietl();
      /*Grupa g = new Grupa(20);

      for (int i = 0; i < 20; ++i) {
            Okrag o = new Okrag(1.1*i);

            g.UstawFigure(i,o);
        }

      g.KlasaFigury();
      g.Wyswietl();
      */
    }

}


///////////////////////////////////Grupa.java//////////////////////////////////



package figura;

public class Grupa extends Figura {
    private Figura[] array;
    private int numberOfElemens;

    public Grupa(int n) {
        numberOfElemens = n;
        array = new Figura[n];
    }

    public void UstawFigure(int i, Figura figure){
        array[i] = figure;
    }

    public void Wyswietl(){
        System.out.print("----------------------------\n");
        System.out.print("|Lp.| Figura | Obwód | Pole|\n");
        System.out.print("----------------------------\n");
        for (int i = 0; i < numberOfElemens; ++i) {
        //System.out.print("| "+(i+1)+"|"+array[i].KlasaFigury()+"|"+array[i].Obwod()+"|"+array[i].PolePowierzchni()+" |\n");
        System.out.printf("| %d | %s |  %.2f  | %.2f |\n",(i+1),array[i].KlasaFigury(),array[i].Obwod(),array[i].PolePowierzchni());
        }
    }


    @Override public String KlasaFigury() {
        return "GrupaFigur";
    }

    @Override public double PolePowierzchni() {
        double sum = 0;
        for (int i = 0; i < numberOfElemens; ++i) {
            sum += array[i].PolePowierzchni();
        }
        return sum;
    }

    @Override public double Obwod() {
      double sum = 0;
        for (int i = 0; i < numberOfElemens; ++i) {
            sum += array[i].Obwod();
        }
        return sum;
    }

}

//////////////////////////////////////////Okrag.java/////////////////////////////////


package figura;


public class Okrag extends Figura {
    double r;

    Okrag(double r){
        this.r = r;
    }

    @Override public String KlasaFigury(){
        return "Okrąg";
    }

     @Override public double PolePowierzchni(){
        return Math.PI*r*r;
    }

      @Override public double Obwod(){
        return 2*(Math.PI*r);
    }

}

///////////////////////////////////////////Prostokat.java////////////////////////////////////


package figura;

public class Prostokat extends Figura{
    double a,b;

    public Prostokat(double a, double b){
        this.a = a;
        this.b = b;
    }

    @Override public String KlasaFigury(){
        return "Prostokąt";
    }

     @Override public double PolePowierzchni(){
        return a*b;
    }

      @Override public double Obwod(){
        return (2*a)+(2*b);
    }
}



////////////////////////////////////////////////Trojkat.java////////////////////////////////////////////////



package figura;

public class Trojkat extends Figura {
    double a,b,c;

    public Trojkat(double a, double b, double c){
       this.a = a;
       this.b = b;
       this.c = c;
    }

    @Override public String KlasaFigury(){
        return "Trójkąt";
    }

     @Override public double PolePowierzchni(){
        double pole,p;
        p = 0.5*(a+b+c);
        return pole = Math.sqrt(p*(p-a)*(p-b)*(p-c));
    }

      @Override public double Obwod(){
        return a+b+c;
    }
}