static void Main(string[] args)
{
ObjectStructure o = new ObjectStructure();
o.Attach(new Element1());
o.Attach(new Element2());
var v1 = new Visitor1();
var v2 = new Visitor2();
o.Accept(v1);
o.Accept(v2);
Console.ReadKey();
}
static void Main(string[] args)
{
IExpressao expressao1 = new Soma(new Numero(10), new Numero(20));
IExpressao expressao2 = new Subtracao(new Numero(20), new Numero(10));
IExpressao expressao3 = new Multiplicacao(expressao1, expressao2);
IExpressao expressao4 = new Divisao(expressao3, new Numero(2));
IExpressao expressao5 = new RaizQuadrada(expressao4);
Console.WriteLine(expressao5.Avalia());
IVisitor impressora1 = new Visitor();
expressao5.Aceita(impressora1);
Console.WriteLine();
IVisitor impressora2 = new Visitor2();
expressao5.Aceita(impressora2);
Console.WriteLine();
}