public class ShapesContainer{
	//state
	public static final int INIT_SIZE=10;
	public static final int RESIZE=10;
	private int numOfShapes=0;
	private Shape[] shapes; //array of shapes
	//constructours
	/**
	 * constructor #1
	 * creates an empty set of shapes
	 */
	public ShapesContainer(){
		Shape[] shapes=new Shape[INIT_SIZE];
		for(int i=0;i<INIT_SIZE; i++){
			shapes[i]=null;
		}
	}
	/**
	 * constructor #2
	 * copy the shapes(shallow copy)
	 * @param other
	 */
	public ShapesContainer(ShapesContainer other){
		if(other!=null){
			Shape[] shapes=new Shape[other.shapes.length];
			for(int i=0;i<shapes.length;i++){
				shapes[i]=other.shapes[i];
			}
		}
		else
			throw new RuntimeException("other is null");
	}
	//behavior
	/**
	 *
	 * @return number of shapes
	 */
	public int getShapesNum(){
		return numOfShapes;
	}
	/**
	 *
	 * @param newShape
	 * @return true if succeed to set new shape
	 */
	public boolean add(Shape newShape){
		for(int i=0;i<numOfShapes;i++){
			int j=0;
			if(newShape.getArea()>shapes[i].getArea()){
				if(numOfShapes<shapes.length){
					Shape[] temp=new Shape[shapes.length+RESIZE];
					for(j=0;j<shapes.length;j++){
						temp[j]=shapes[j];
					}
					for(j=shapes.length-1;j<temp.length;j++){
						temp[j]=null;
					}
					shapes=temp;
				}
				for(j=numOfShapes;j>=i;j++){
					shapes[j+1]=shapes[j];
				}
				shapes[j]=newShape;
				numOfShapes=numOfShapes+1;
				return true;
			}
			if(newShape.getArea()==shapes[i].getArea() && newShape==shapes[i]){
				return false;
			}
		}
		shapes[numOfShapes]=newShape;
		numOfShapes=numOfShapes+1;
		return true;
	}
	/**
	 *
	 * @param toRemove
	 * @return true if succeed to remove the shape
	 */
	public boolean remove(Shape toRemove){
		for(int i=0; i<numOfShapes; i++){
			if(toRemove.getArea()==shapes[i].getArea() && toRemove==shapes[i]){
				for(int j=i;j<numOfShapes; j++){
					shapes[j]=shapes[j+1];
				}
				shapes[numOfShapes]=null;
				numOfShapes=numOfShapes-1;
				return true;
			}
		}
		return false;
	}
	/**
	 *
	 * @param i
	 * @return true if succeed to remove the shape
	 */
	public boolean remove(int i){
		if(i>=0 && i<=numOfShapes){
			remove(shapes[i]);
			return true;
		}
		else
			return false;
	}
	public Shape getShape(int i){
		if(i>=0 && i<=numOfShapes){
			return shapes[i];
		}
		else

	}
}