perfectly executed BINARY SEARCH TREE

//hi friends at last here it is the perfectly executed economical BST program

# include <conio.h>
# include <process.h>
# include <iostream.h>
# include <alloc.h>
static int cnt;
struct node
{
 int ele;
 node *left;
 node *right;
};

typedef struct node *nodeptr;
  class bstree
{
 public:
  void insert(int,nodeptr &);
  void del(int,nodeptr &);
  int deletemin(nodeptr &);
  void find(int,nodeptr &);
  void preorder(nodeptr);
  void inorder(nodeptr);
  void postorder(nodeptr);

};

void bstree::insert(int x,nodeptr &p)
{
 if (p==NULL)
 {
  p = new node;
  p->ele=x;
  p->left=NULL;
  p->right=NULL;
 }
 else
 {
  if (x < p->ele)
   insert(x,p->left);
  else if (x>p->ele)
   insert(x,p->right);
  else
   cout<<"Element already Exits !";
 }

}

void bstree:: del(int x,nodeptr &p)
{
 nodeptr d;
 if (p==NULL)
  cout<<"Element not found ";
 else if (x < p->ele)
  del(x,p->left);
 else if (x > p->ele)
  del(x,p->right);
 else if ((p->left == NULL) && (p->right ==NULL))
 {
  d=p;
  free(d);
  p=NULL;
 }
  else if (p->left == NULL)
 {
  d=p;
  free(d);
  p=p->right;
 }
 else if (p->right ==NULL)
 {
  d=p;
  p=p->left;
  free(d);
 }
 else
 p->ele=deletemin(p->right);
}

int bstree::deletemin(nodeptr &p)
{
 int c;cnt=0;
 if (p->left == NULL)
 {
  c=p->ele;
  p=p->right;
  return c;
 }
 else
  c=deletemin(p->left);
  return c;
}
void bstree::find(int x,nodeptr &p)
{
 if (p==NULL)
  cout<<"Element not found  !";
 else
 {
  if (x <p->ele)
   find(x,p->left);
  else if ( x> p->ele)
   find(x,p->right);
  else
   cout<<"Element Found !";
 }
}
void bstree::preorder(nodeptr p)
{
 if (p!=NULL)
 {
  cout<<p->ele<<"-->";
  preorder(p->left);
  preorder(p->right);
 }
}
void bstree::inorder(nodeptr p)
{

 if (p!=NULL)
 {
  inorder(p->left);
  cout<<p->ele<<"-->";cnt++;
  inorder(p->right);
 }
}

void bstree::postorder(nodeptr p)
{
 if (p!=NULL)
 {
  postorder(p->left);
  postorder(p->right);
  cout<<p->ele<<"-->";
 }
}
int main()
{
int ch,x;
bstree bst;
char c='y';
nodeptr root;
root=NULL;
do
{

 clrscr();
 cout<<"   Binary Search Tree";
 cout<<"\n1.Insertion\n2.Deletion\n3.Find";
 cout<<"4.Preorder\n5.Inorder\n6.Postorder\n7.Size";
 cout<<"\nEnter your choice :";
 cin>>ch;
 switch(ch)
 {
 case 1:
  cout<<"  1.Insertion";
  cout<<"Enter Node Element : ";
  cin>>x;
  bst.insert(x,root);
  break;

 case 2:
  cout<<"  2.Deletion";
  cout<<"Enter Element to Delete ?";
  cin>>x;
  bst.del(x,root);
  break;
 case 3:
  cout<<"  3.Find";
  cout<<"Enter the element to Search ?";
  cin>>x;
  bst.find(x,root);
  break;

 case 4:
  cout<<"  4.Preorder";
  if (root==NULL)
   cout<<"\nTree is empty";
  else
  {
    cout<<"\nPreorder traversal is :";
  bst.preorder(root);
  }
  break;

 case 5:
  cout<<"  5.Inorder";
  if (root==NULL)
   cout<<"\nTree is empty";
  else
  {
  cout<<"\nInorder traversal is :";
  bst.inorder(root);
  }
  break;

 case 6:
  cout<<"  6.Postorder";
  if (root==NULL)
   cout<<"\nTree is empty";
  else
  {
  cout<<"\nPostorder traversal is :";
  bst.postorder(root);
  }
  break;
 case 7: cout<<"\nnumber of nodes :"<<cnt;
  break;
 default:cout<<"invalid option..";
  break;
 }
 cout<<"Continue (y/n) ?";
 cin>>c;
 }while (c!='n');
 return 0;
}

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