9-11.h

《c++语言程序设计》例题程序

//9-11.h
#ifndef TREENODE_CLASS 
#define TREENODE_CLASS

#ifndef NULL
const int NULL = 0;
#endif  // NULL

template <class T>
class TreeNode
{
   private:
      TreeNode<T> *left;    //左指针
      TreeNode<T> *right;   //右指针

   public:
      T data;    //结点数据
   
      // 构造函数
      TreeNode (const T& item, TreeNode<T> *lptr = NULL,
                TreeNode<T> *rptr = NULL);
   
      // 访问指针域的函数
      TreeNode<T>* Left(void) const;      //取得左指针
      TreeNode<T>* Right(void) const;     //取得右指针
   
      // 删除当前结点的左右子树
      void release();
};

// 构造函数，初始化数据域和指针域
template <class T>
TreeNode<T>::TreeNode (const T& item, TreeNode<T> *lptr,
    TreeNode<T> *rptr): data(item), left(lptr), right(rptr)
{}

//取得左指针
template <class T>
TreeNode<T>* TreeNode<T>::Left(void) const
{
   return left;
}

//取得右指针
template <class T>
TreeNode<T>* TreeNode<T>::Right(void) const
{
   return right;
}

// 删除当前结点的左右子树
template <class T>
void TreeNode<T>::release()
{
if(left)
{  //删除左子树
   left->release();
   delete left;
   left=NULL;
}
if(right)
{  //删除右子树
   right->release();
   delete right;
   right=NULL;
}
}

#endif // TREENODE_CLASS