class Node
{
 public int iData ;
 public float fData ;
 public Node left ;
 public Node right ;
 //方法
 public Node(int iData,float fData){}
 public void displayNode(){} 
}
class Tree
{
 Node root ;//树根
 //方法
 public void insert(){}
 public void displayTree(){}
 public void find(){}
 public void delete(){}
}

 //插入子节点
 public void insert(int iData ,float fData)
 {
 Node newNode = new Node(iData,fData) ;
 if(root == null)
 root = newNode ;
 else
 {
 Node current = root ;
 Node parent ;
 while(true)//寻找插入的位置 
 {
 parent = current ;
 if(iData<current.iData)
 {
 current = current.left ;
 if(current == null)
 {
 parent.left = newNode ;
 return ;
 }
 }
 else
 {
 current =current.right ;
 if(current == null)
 {
 parent.right = newNode ;
 return ;
 }
 }
 }
 }
 }

//中序遍历方法
 public void inOrder(Node localRoot)
 {
 if(localRoot != null)
 {
 inOrder(localRoot.left) ;//调用自身来遍历左子树
 localRoot.displayNode() ;//访问这个节点
 inOrder(localRoot.right) ;//调用自身来遍历右子树
 }
 }

//查找某个节点
 public Node find(int iData)
 {
 Node current = root ;
 while(current.iData != iData)
 {
 if(current.iData<iData)
 current = current.right ;
 else
 current = current.left ;
 if(current == null)
 return null ;
 }
 return current ;
 }

//查找关键字最小的节点
 public Node findMinNode()
 {
 Node current , last ;
 last = null ;
 current = root ;
 if(current.left == null)
 return current ;
 else
 {
 while(current != null)
 {
 last = current ;
 current = current.left ;
 }
 return last ;
 }
 }

public boolean delete(int key)
 {
 //先找到需要删除的节点
 Node current = root ;
 Node parent = root ;
 boolean isLeftChild = false ;
 while(current.iData != key)//显然，当current.iData == key 时，current 就是要找的节点
 {
 parent = current ;
 if(key < current.iData)
 {
 isLeftChild = true ;
 current = current.left ;
 }
 else
 {
 isLeftChild = false ;
 current = current.right ;
 }
 if(current == null)//找不到key时返回false
 return false ;
 }
 //continue ........
 }

//接上................
 //分情况考虑删除的节点
 //删除的节点为叶节点时
 if(current.left == null && current.right == null)
 {
 if(current == root)
 root = null ;
 else
 if(isLeftChild)
 parent.left = null ;
 else
 parent.right = null ;
 }
//continue...........

//接上.......
//删除的节点有一个子节点
 else
 if(current.right == null)//删除的节点只有一个左子节点时
 {
 if(current == root)//要删除的节点为根节点
 root = current.left ;
 else
 if(isLeftChild)//要删除的节点是一个左子节点
 parent.left = current.left ;
 else
 parent.right = current.left ;//要删除的节点是一个右子节点
 }
 else
 if(current.left == null)//删除的节点只有一个右子节点时
 {
 if(current == root)//要删除的节点为根节点
 root = current.right ;
 else
 if(isLeftChild)//要删除的节点是一个左子节点
 parent.left = current.right ;
 else
 parent.right = current.right ;//要删除的节点是一个右子节点
 }
//continue.......

 //返回后继节点
 private Node getSuccessor(Node delNode)
 {
 Node successorParent = delNode ;//后继节点的父节点
 Node successor = delNode ;//后继节点
 Node current = delNode.right ;//移动到位置节点位置
 while(current != null)
 {
 successorParent = successor ;
 successor = current ;
 current = current.left ;
 }
 if(successor != delNode.right)
 {
 successorParent.left = successor.right ;
 successor.right = delNode.right ;
 }
 return successor ;
 }

//要删除的节点为左子节点时
parent.left = successor ;
successor.left = current.left ;
//要删除的节点是右子节点时
parent.right = successor ;
successor.left = current.left ;

//假如要删除的节点为右子节点
successorParent.left = successor.right ;//第一步
successor.right = current.right ;//第二步
parent.right = successor ;
successor.left = current.left ;
//假设要删除的节点为左子节点
successorParent.left = successor.right ;
successor.right = current.right ;
parent.left = successor ;
successor.left = current.left ;

//接上 
 //删除的节点有两个子节点
 else
 {
 Node successor = getSuccessor(current) ;//找到后继节点
 if(current == root)
 root = successor ;
 else
 if(isLeftChild)
 parent.left = successor ;
 else
 parent.right = successor ;
 successor.left = current.left ;
 }
 //continue....

//删除某个节点
 public boolean delete(int key)
 {
 //先找到需要删除的节点
 Node current = root ;
 Node parent = root ;
 boolean isLeftChild = false ;
 while(current.iData != key)//显然，当current.iData == key 时，current 就是要找的节点
 {
 parent = current ;
 if(key < current.iData)
 {
 isLeftChild = true ;
 current = current.left ;
 }
 else
 {
 isLeftChild = false ;
 current = current.right ;
 }
 if(current == null)//找不到key时返回false
 return false ;
 }
 //分情况考虑删除的节点
 //删除的节点为叶节点时
 if(current.left == null && current.right == null)
 {
 if(current == root)
 root = null ;
 else
 if(isLeftChild)
 parent.left = null ;
 else
 parent.right = null ;
 }
 //删除的节点有一个子节点
 else
 if(current.right == null)//删除的节点只有一个左子节点时
 {
 if(current == root)//要删除的节点为根节点
 root = current.left ;
 else
 if(isLeftChild)//要删除的节点是一个左子节点
 parent.left = current.left ;
 else
 parent.right = current.left ;//要删除的节点是一个右子节点
 }
 else
 if(current.left == null)//删除的节点只有一个右子节点时
 {
 if(current == root)//要删除的节点为根节点
 root = current.right ;
 else
 if(isLeftChild)//要删除的节点是一个左子节点
 parent.left = current.right ;
 else
 parent.right = current.right ;//要删除的节点是一个右子节点
 }
 //删除的节点有两个子节点
 else
 {
 Node successor = getSuccessor(current) ;//找到后继节点
 if(current == root)
 root = successor ;
 else
 if(isLeftChild)
 parent.left = successor ;
 else
 parent.right = successor ;
 successor.left = current.left ;
 }
 return true ;
 }