该题是阿里2014年校园招聘的一道笔试题，我自己写了一下，代码如下：

#include<iostream>
#include<cmath>
#include <conio.h>
#include<vector>using namespace std;static int value = 0;
static int Vmax ;
static int Vmin ;struct tree
{int data;tree *left,*right;
};class Btree
{static int n;static int m;
public:tree *root;Btree(){root=NULL;}void create_Btree(int);void Preorder(tree *);                  //先序遍历void display1() {Preorder(root); cout<<endl;} 
}; int Btree::n=0;
int Btree::m=0;void Btree::create_Btree(int x)
{tree *newnode=new tree;newnode->data=x;newnode->right=newnode->left=NULL;if(root==NULL)root=newnode;else{tree *back;tree *current=root;while(current!=NULL){back=current;if(current->data>x)current=current->left;elsecurrent=current->right;}if(back->data>x)back->left=newnode;elseback->right=newnode;}
}void Btree::Preorder(tree *temp)    //这是先序遍历二叉树，采用了递归的方法。
{int temp_value = 0;if(temp!=NULL){if(temp->data>Vmax){Vmax = temp->data;}else if(temp->data<Vmin){Vmin = temp->data;}temp_value = abs(Vmax-Vmin);if(temp_value>value){value = temp_value;}cout<<temp->data<<endl;Preorder(temp->left);Preorder(temp->right);}
}int main()
{vector<int> vec;Btree A;int a;while(cin>>a){//要先push_back(a)再判断，否则最后一个跟回车混在一起，没有push进去vec.push_back(a);if(getchar()==10){break;}}int k = vec.size();for(int i = 0;i<vec.size();i++){A.create_Btree(vec[i]);}cout<<endl;Vmax = vec[0];Vmin = vec[1];cout<<endl<<"先序遍历序列"<<endl;A.display1();cout<<"节点间最大值为：\n";cout<<value<<endl;
}