二叉树创建元素计数与显示_怎么建二叉树，输入元素-优快云博客

//shu_3.h

#include <iostream>
using namespace std;

struct tree
{
int data;
tree *left,*right;
};

class Btree
{
public:
tree *root;
Btree()
{
root=NULL;
}

void create(int);
void print(tree *);
int count(tree *);
};

//shu_3.app

#include "shu_3.h"

void Btree::create(int x)
{
tree *newnode=new tree;
newnode->data=x;
newnode->left=newnode->right=NULL;

if(root==NULL)
  root=newnode;
else
{
    tree *current=root;
tree *back;
     while(current!=NULL)
  {
   back=current;
   if(x<current->data)
   current=current->left;
   else
    current=current->right;
  }
if(x<back->data)
   back->left=newnode;
  else
   back->right=newnode;
}

}

void Btree::print(tree *p)
{
if(p!=NULL)
  {
   cout<<p->data<<" ";
   print(p->left);
   print(p->right);

}
}

int Btree::count(tree *p)
{
if(p==NULL)
return 0;
else
return count(p->left)+count(p->right)+1;
}

//main.cpp

#include "shu_3.h"

int main()
{
Btree s;
int array[]={1,2,4,5,3};
    for(int i=0;i<5;i++)
{
  cout<<array[i]<<" ";
  s.create(array[i]);
}
cout<<endl;
s.print(s.root);
cout<<endl;
cout<<s.count(s.root)<<endl;
return 0;
}