數據結構與算法(C#實現)系列---樹(二)

                    Heavenkiller(原創)

         public class InOrder:IPrePostVisitor

         {

              private IVisitor visitor;

              public InOrder(IVisitor _vis){visitor=_vis;}

              #region IPrePostVisitor 成員

              public void PreVisit(object _obj)

              {

                   // TODO:  添加 InOrder.PreVisit 實現

              }

              public void Visit(object _obj)

              {

                   // TODO:  添加 InOrder.Visit 實現

                   this.visitor.Visit(_obj);

              }

              public void PostVisit(object _obj)

              {

                   // TODO:  添加 InOrder.PostVisitor 實現

              }

              #endregion

          }

         public class PostOrder:IPrePostVisitor

         {

              private IVisitor visitor;

              public PostOrder(IVisitor _vis){visitor=_vis;}

              #region IPrePostVisitor 成員

              public void PreVisit(object _obj)

              {

                   // TODO:  添加 PostOrder.PreVisit 實現

              }

              public void Visit(object _obj)

              {

                   // TODO:  添加 PostOrder.Visit 實現

              }

              public void PostVisit(object _obj)

              {

                   // TODO:  添加 PostOrder.PostVisitor 實現

                   this.visitor.Visit(_obj);

              }

              #endregion

         }

         protected class EnumVisitor:IVisitor

         {

              Queue thisQueue;

              public EnumVisitor(Queue _que)

              {

                   this.thisQueue=_que;

              }

              #region IVisitor 成員

              public void Visit(object _obj)

              {

                   // TODO:  添加 EnumVisitor.Visit 實現

                   this.thisQueue.Enqueue(_obj);

              }

              #endregion

         }

         #region IEnumerable 成員

         public IEnumerator GetEnumerator()

         {

              // TODO:  添加 Tree.GetEnumerator 實現

              EnumVisitor vis=new EnumVisitor(this.keyqueue);

              switch (this.traversaltype)

              {

                   case TraversalType.Breadth:

                       BreadthFirstTraversal(vis);

                        break;

                   case TraversalType.PreDepth:

                       PreOrder preVis=new PreOrder(vis);

                       DepthFirstTraversal(preVis);                      

                       break;

                   case TraversalType.InDepth:

                       InOrder inVis=new InOrder(vis);

                       DepthFirstTraversal(inVis);                   

                       break;

                  case TraversalType.PostDepth:

                       PostOrder postVis=new PostOrder(vis);

                       DepthFirstTraversal(postVis);                     

                       break;

                   default:

                       Console.WriteLine("WARNING:please set a travel type first!--void SetTraversalType(TraversalType _type) ");

                       //throw new Exception("WARNING:please set a travel type first!");//if not set a type, a exception will happen

                       break;

              }

              return this.keyqueue.GetEnumerator();

         }

         #endregion