如何在二叉搜索树中查找节点值大于指定值

时间:2010-05-18 10:40:52

标签: binary-search

我有一棵红黑树,基本操作是插入,删除,遍历,后序和预订等。

我希望创建一个方法,该方法可以返回树中大于指定值的节点。同样少于此。

任何人都可以指出一些伪代码/算法(它们可能意味着同样的事情)

干杯

1 个答案:

答案 0 :(得分:0)

下面是我创建的代码,对于大于或等于指定值的节点,按升序显示我的节点的测试很好。有人可以查看我的代码并建议改进,如果可能的话,建议我如何为我的LessThan方法执行此操作。目前我的LessThan方法按降序返回,我只是看不到如何让它升序。欢呼声。

 // --------------------------------------------------------------------------------
// GetNodesGreaterThan
// --------------------------------------------------------------------------------
/** \fn void  RedBlackTree<T>::GetNodesGreaterThan(T &data)
 *  \brief This method checks to see if tree is empty otherwise calls the 
 *          recursive the GreaterThan method.
 *  \param templated
 *  \return void
 */
template <class T>
void  RedBlackTree<T>::GetNodesGreaterThan(T &data)
{
    GreaterThan(m_root, data);
}

// --------------------------------------------------------------------------------
// GreaterThan
// --------------------------------------------------------------------------------
/** \fn void RedBlackTree<T>::GreaterThan(NodeType<T> *p, const T &data) const
 *  \brief This method finds the nodes in the tree that are greater than  or equal to 
 *          a specified value and puts nodes into a list.
 *  \param templated pointer
 *  \param constant template
 *  \return void
 */
template <class T>
void RedBlackTree<T>::GreaterThan(NodeType<T> *p, const T &data) const
{
    if ( p != NULL)                                         // we have hit a leaf node
    {
        if ((p->m_data == data) || (data < p->m_data)){     // record the node whos value is
            GreaterThan(p->m_lLink, data);                  // move down left link
            //cout << p->m_data << " ";                     // Display data (debug purpose)
        }
        GreaterThan(p->m_rLink, data);                      // move down right link 
    }
}

// --------------------------------------------------------------------------------
// GetNodesLessThan
// --------------------------------------------------------------------------------
/** \fn void  RedBlackTree<T>::GetNodesLessThan(T &data)
 *  \brief This method checks to see if tree is empty otherwise calls the 
 *          recursive the LessThan method.
 *  \param template
 *  \return void
 */
template <class T>
void  RedBlackTree<T>::GetNodesLessThan(T &data)
{
    ClearList();                                            // clears the node list
    LessThan(m_root, data);
}

// --------------------------------------------------------------------------------
// LessThan
// --------------------------------------------------------------------------------
/** \fn void RedBlackTree<T>::LessThan(NodeType<T> *p, const T &data) const
 *  \brief This method finds the nodes in the tree that are less than  or equal to 
 *          a specified value and puts nodes into a list.
*  \param templated pointer
 *  \param constant template
 */
template <class T>
void RedBlackTree<T>::LessThan(NodeType<T> *p, const T &data) const
{
    if ( p != NULL)
    {
        if ((p->m_data == data) || (data > p->m_data)){     // record the node whos value is
            LessThan(p->m_rLink, data);                     // move down left link
            //cout << p->m_data << " ";                     // Display data (debug purpose)
            //m_list[m_countOfElements] = p->m_data;            // add to list
            //m_countOfElements++;                              // increment # of elements
        }
        LessThan(p->m_lLink, data);                         // move down left link
    }
}