一棵排序二叉树，令 f=(最大值+最小值)/2，设计一个算法，找出距离f值最近、大于f值的结点。复杂度如果是O(n2)则不得分。

#include "stdafx.h"   #include <iostream>   #include <cassert>   #include <iterator>   using namespace std;  struct Node  {      int elememt;      Node *pLeft;      Node *pRight;      Node(int ele, Node *left = NULL, Node *right = NULL)          :elememt(ele), pLeft(left), pRight(right){}  };  //插入元素   void InsertNode(Node *&root, int ele)  {      if(NULL == root)          root = new Node(ele);      else if (root->elememt > ele)          InsertNode(root->pLeft, ele);      else if (root->elememt < ele)          InsertNode(root->pRight, ele);  }  //创建二叉查找树   void CreateTree(Node *&root, int arr[], int len)  {      for (int i = 0; i < len; i++)          InsertNode(root, arr[i]);  }  //中序输出树   void MiddlePrint(Node *root)  {      if (NULL == root)          return;      MiddlePrint(root->pLeft);      cout<<root->elememt<<" ";      MiddlePrint(root->pRight);  }  //获得最大值   int GetMaxValue(Node *root)  {      assert(root != NULL);      while (root->pRight != NULL)          root = root->pRight;      return root->elememt;  }  //获得最小值   int GetMinValue(Node *root)  {      assert(NULL != root);      while (root->pLeft != NULL)          root = root->pLeft;      return root->elememt;  }  //查找指定的结点   Node *FindNode(Node *root, int target)  {      assert(NULL != root);      int diff = INT_MAX;      Node *p = NULL;      while (root != NULL)      {          if (root->elememt > target)          {              if (root->elememt - target < diff)              {                  diff = root->elememt - target;                  p = root;              }              root = root->pLeft;          }          else if (root->elememt < target)          {              root = root->pRight;          }      }      return p;  }  int main()  {      int arr[] = {20, 8, 22, 4, 12, 10, 14};      int len = sizeof(arr) / sizeof(int);      Node *root = NULL;      CreateTree(root, arr, len);      MiddlePrint(root);      printf("/n");      int minValue = GetMinValue(root);      int maxValue = GetMaxValue(root);      Node *node = FindNode(root, (minValue + maxValue) / 2);      assert(NULL != node);      printf("%d/n", node->elememt);  }