package arrayListDemo1;

 

import java.io.IOException;

import java.util.*;

//interface

interface IHinh {

      int tinhDT();

      void hienthi();

}

 

abstract class hinh implements IHinh {

      public abstract int tinhDT();

      public abstract void hienthi();

}

 

class tamgiac extends hinh {

      public int tinhDT() {

           return 100;

      }

 

      public void hienthi() {

           System.out.println("Tam giac");

      }

}

 

class hinhvuong extends hinh {

      public int tinhDT() {

           return 500;

      }

      public void hienthi() {

           System.out.println("Hinh vuong");

      }

}

class listDemo{

      ArrayList<hinh> list = new ArrayList<hinh>();

      int n=0;

      char chon,loai;

      void input() throws IOException {

           hinh[] h = new hinh[100];

           do

           {

                 System.out.println("Tam giac hay hinh vuong (t/v)?");

                 loai = (char) System.in.read();

                 if (loai=='T' || loai=='t')

                      h[n]=new tamgiac();   

                 else

                      h[n]=new hinhvuong();

                 //them phan tu vao ArrayList

                 list.add(h[n]);

                 System.in.skip(loai);

                 h[n++].tinhDT();

                 System.out.println("Tiep tuc (C/K)?");

                 chon = (char) System.in.read();

                 System.in.skip(chon);

                 if ((n==100)||(chon=='K')||(chon=='k'))

                      break;

           }

           while (true);

      }

      void output() {

           for (int i = 0; i < list.size(); i++) {

                 System.out.println(list.get(i).tinhDT());

                 list.get(i).hienthi();

           }

      }

      void xoa(int id) {

           list.remove(id);

      }

}

public class demo {

      public static void main(String[] args) throws IOException {

           listDemo list  = new listDemo();

           list.input();

           list.output();

           list.xoa(0);

           list.output();

      }

}

Trương Đình Huy