udemy_33. CarpetCostCalculator

public class Floor {
    private double width;
    private double length;

    public Floor(double width, double length) {
        if (width<0)
            this.width=0;
        else
            this.width = width;
        if (length<0)
            this.length = 0;
        else
            this.length=length;
    }

    public double getArea(){
        return width*length;
    }
}

public class Carpet {
    private double cost;

    public Carpet(double cost) {
        if (cost<0)
            this.cost = 0;
        else
            this.cost=cost;
    }

    public double getCost() {
        return cost;
    }
}

public class Calculator {
    private Floor floor;
    private Carpet carpet;

    public Calculator(Floor floor, Carpet carpet) {
        this.floor = floor;
        this.carpet = carpet;
    }

    public double getTotalCost(){
        return floor.getArea()*carpet.getCost();
    }
}