Suggest some ways to improve it(since I have made root public and want to make it Private).This is code for Inorder, Preorder, Postorder Traversal of a Tree.

#include<iostream.h> #include<conio.h>  struct Node {   int data;   Node *left;   Node *right; };   class Tree {   private:     Node *p;   public:     Node *root;     Tree()     {       root=NULL;     }     void Insertion();     void Traversal();   protected:     void SearchPos(Node *);     void Inorder_Traversal(Node *);     void Preorder_Traversal(Node *);     void Postorder_Traversal(Node *); };  void Tree::Insertion() {   p=new Node;   p->left=p->right=NULL;   if(root==NULL)   {     cout<<"Enter Root Value to be inserted:";     cin>>p->data;     root=p;   }   else   {     cout<<"\nEnter Value to be inserted:";     cin>>p->data;     SearchPos(root);   } }  void Tree::SearchPos(Node *tmp) {   if(p->data<tmp->data && tmp->left==NULL)   {     tmp->left=p;     return;   }   else if(p->data>tmp->data && tmp->right==NULL)   {     tmp->right=p;     return;   }   else if(p->data<tmp->data && tmp->left!=NULL)   {     SearchPos(tmp->left);   }   else if(p->data>tmp->data && tmp->right!=NULL)   {     SearchPos(tmp->right);   } }  void Tree::Traversal() {   cout<<"\nInorder Traversal:";   Inorder_Traversal(root);   cout<<"\nPreorder Traversal:";   Preorder_Traversal(root);   cout<<"\nPostorder Traversal:";   Postorder_Traversal(root); }  void Tree::Inorder_Traversal(Node *tmp) {   if(tmp->left==NULL && tmp->right==NULL)   {     cout<<tmp->data<<" ";     return;   }   else if(tmp->left!=NULL)   {     Inorder_Traversal(tmp->left);   }   cout<<tmp->data<<" ";   if(tmp->right!=NULL)   {     Inorder_Traversal(tmp->right);   } }  void Tree::Preorder_Traversal(Node *tmp) {   if(tmp->left==NULL && tmp->right==NULL)   {     cout<<tmp->data<<" ";     return;   }   else if(tmp->left!=NULL)   {     cout<<tmp->data<<" ";     Preorder_Traversal(tmp->left);   }   if(tmp->right!=NULL)   {     Preorder_Traversal(tmp->right);   } }  void Tree::Postorder_Traversal(Node *tmp) {   if(tmp->left==NULL && tmp->right==NULL)   {     cout<<tmp->data<<" ";     return;   }   else if(tmp->left!=NULL)   {     Postorder_Traversal(tmp->left);   }   if(tmp->right!=NULL)   {     Postorder_Traversal(tmp->right);     cout<<tmp->data<<" ";   } }  void main() {   clrscr();   char choice;   Tree t;   do   {     t.Insertion();     cout<<"\nMore to Insert???Enter(y/n):";     cin>>choice;   }while(choice=='y'||choice=='Y');   t.Traversal();   getch(); }