static void Main(string[] args)
{
Leaf apple = new Leaf("苹果", 5);
Leaf banana = new Leaf("香蕉", 2);
Leaf pineapple = new Leaf("菠萝", 20);
Leaf pear = new Leaf("梨", 4);
Composite red = new Composite("红袋子");
Composite blue = new Composite("蓝袋子");
Composite black = new Composite("黑袋子");
red.ADD(apple);
red.ADD(banana);
blue.ADD(pineapple);
blue.ADD(apple);
blue.ADD(pear);
black.ADD(red);
black.ADD(blue);
black.ADD(pear);
Console.WriteLine("总价" + black.Charge());
}