數據結構與算法 - C#實現N叉樹(2)

public override uint Degree
         {
              get
              {
                   return this.degree;
              }
         }
         //只用於空樹結點
         public virtual void AttachKey(object _obj)
         {
              if(!IsEmpty())
                   throw new Exception("My:this node must be a empty tree node!");
              this.key=_obj;
              this.treeList=new ArrayList();//產生一個degree長的數組,並將其初始化為空樹
              this.treeList.Capacity=(int)this.degree;
              for(int i=0;i<this.degree;i++)
              {
                   treeList.Add(new NaryTree(this.degree));
              }
              /*
              foreach(object tmpObj in this.treeList)
              {
                   tmpObj=new NaryTree(this.degree);
              }
              */
         }
         //只用於葉子結點，將葉子結點變為一個空結點，並返回葉子結點關鍵字的引用
         public virtual object DetachKey()
         {
              if(!IsLeaf())
                   throw new Exception("My:this node must be a leaf node!");
              object result=this.key;//store this leaf node temporary
              this.key=null;
              this.treeList=null;
              return result;
         }
         //將子樹連接到指定樹的第num個結點上，前提是這個結點必須是空結點,並且度數相同，否則拋出異常
         public virtual void AttachSubtree(uint num,NaryTree _naryTree)
         {
              if(this.IsEmpty())
                   throw new Exception("My:it can't be a empty tree!");
              if(!(this[num-1].IsEmpty()) | this.degree!=_naryTree.degree )
                   throw new Exception("My:this[i-1] must be empty and they should have the same degree!");
              this[num-1]=_naryTree;
         }
         //僅為非空樹定義，從給定樹中刪去它的第i棵子樹並連上一個空樹,度數相同，並且返回刪除的子樹引用
         public virtual NaryTree DetachSubtree(uint num)
         {
              if (IsEmpty())
                   throw new Exception("My:it can't be empty! ");
              NaryTree tmpTree=this;
              ((NaryTree)this[num-1]).key=null;
              ((NaryTree)this[num-1]).treeList=null;
              return this;
         }
     }
}