Implement of Binary Search Tree(BST) and its Operations in CPP

Here a CPP code to make a BST and perform its all operations.

#include <iostream.h>
class btree
{
 private :
  struct node
  {
   node *left ;
   char data ;
   node *right ;
  } *root ;
  char *arr ;
  int *lc ;
  int *rc ;
 public :
  btree ( char *a, int *l, int *r, int size ) ;
  void insert ( int index ) ;
  static node* buildtree ( char *a, int *l, int *r, int index ) ;
  void display( ) ;
  static void inorder ( node *sr ) ;
  ~btree( ) ;
  static void del ( node *sr ) ;
} ;
btree :: btree ( char *a, int *l, int *r, int size )
{
 root = NULL ;
 arr = new char[size] ;
 lc = new int[size] ;
 rc = new int[size] ;
 for ( int i = 0 ; i < size ; i++ )
 {
  * ( arr + i ) = * ( a + i ) ;
  * ( lc + i ) = * ( l + i ) ;
  * ( rc + i ) = * ( r + i ) ;
 }
}
void btree :: insert ( int index )
{
 root = buildtree ( arr, lc, rc, index ) ;
}
node* btree :: buildtree ( char *a, int *l, int *r, int index )
{
 node *temp = NULL ;
 if ( index != -1 )
 {
  temp = new node ;
  temp -> left = buildtree ( a, l, r, * ( l + index ) ) ;
  temp -> data = * ( a + index ) ;
  temp -> right = buildtree ( a, l, r, * ( r + index ) ) ;
 }
 return temp ;
}
void btree :: display( )
{
 inorder ( root ) ;
}
void btree :: inorder ( node *sr )
{
 if ( sr != NULL )
 {
  inorder ( sr -> left ) ;
  cout << sr -> data << "\t" ;
  inorder ( sr -> right ) ;
 }
}
btree :: ~btree( )
{
 delete arr ;
 delete lc ;
 delete rc ;
 del ( root ) ;
}
void btree :: del ( node *sr )
{
 if ( sr != NULL )
 {
  del ( sr -> left ) ;
  del ( sr -> right ) ;
 }
 delete sr ;
}
void main( )
{
 char a[ ] = { 'A', 'B', 'C', 'D', 'E', 'F', 'G', '\0', '\0', 'H' } ;
 int  l[ ] = {  1,   3,   5,   -1,   9,  -1,  -1,   -1,   -1,  -1 } ;
 int  r[ ] = {  2,   4,   6,   -1,  -1,  -1,  -1,   -1,   -1,  -1 } ;
 int sz = sizeof ( a ) ;
 btree bt ( a, l, r, sz ) ;
 bt.insert( 0 ) ;
 cout << "\nIn-order Traversal: " << endl ;
 bt.display( ) ;
}