BINARY SEARCH TREE

/*Binary search tree with all the Recursive and non Recursive


#include<iostream.h>
#include<conio.h>
#include<stdlib.h>

class binarynode
{
 public:
   int data;
   binarynode *left;
   binarynode *right;
};

class binsrctree
{
 private:
   binarynode *root;
   void inorder_rec(binarynode *);
   void inorder_non_rec(binarynode *);
   void preorder_rec(binarynode *);
   void preorder_non_rec(binarynode *);
   void postorder_rec(binarynode *);
   void postorder_non_rec(binarynode *);
 public:
   binsrctree()
   {
    root=NULL;
   }
   void insert(int );
   void print_inorder_rec();
   void print_inorder_non_rec();
   void print_preorder_rec();
   void print_preorder_non_rec();
   void print_postorder_rec();
   void print_postorder_non_rec();
};

class stack
{
 int top;
 binarynode *stackel[20];
  public:
   stack()
   {
    top=-1;
   }
  void push(binarynode *);
  binarynode* pop();
  int empty()
  {
   if(top==-1)
   return(1);

   return(0);
  }
};

void stack::push(binarynode *node)
{
 stackel[++top]=node;
}

binarynode *stack::pop()
{
 return(stackel[top--]);
}

class stack_int
{
 int top;
 int stack_int[20];
  public:
   stack_int()
   {
    top=-1;
   }
  void push(int flag);
  int pop();
  int empty_int()
  {
   if(top==-1)
   return(1);

   return(0);
  }
};

void stack_int::push(int flag)
{
 stack_int[++top]=flag;
}

int stack_int::pop()
{
 return(stack_int[top--]);
}
/*---------------------------------------------------------------------*/
/* fUNCTION TO INSERT A NODE IN THE TREE */
/*---------------------------------------------------------------------*/
void binsrctree::insert(int val)
{
 binarynode *temp,*prev,*curr;
 temp=new binarynode;
 temp->data=val;
 temp->left=temp->right=NULL;

 if(root==NULL)
 {
  root=temp;
 }
 else
 {
   curr=root;
   while(curr!=NULL)
   {
    prev=curr;
    if(temp->data<curr->data)
       curr=curr->left;
    else
       curr=curr->right;
   }
   if(temp->data<prev->data)
      prev->left=temp;
   else
      prev->right=temp;
  }
}

/* ------------------------------------------------*/
/*INORDER RECURSIVE TRAVERSAL*/
/*-------------------------------------------------*/

void binsrctree::inorder_rec(binarynode *root)
{
  if(root!=NULL)
  {
   inorder_rec(root->left);
   cout<<root->data<<"    ";
   inorder_rec(root->right);
  }
}

/*--------------------------------------------------*/
/*INORDER NON RECURSIVE TRAVERSAL*/
/*--------------------------------------------------*/

void binsrctree::inorder_non_rec(binarynode *root)
{
 stack stk;
 binarynode *temp;
 if(root!=NULL)
 {
  temp=root;
  do
  {
   while(temp!=NULL)
   {
      stk.push(temp);
      temp=temp->left;
   }/*end while*/
   if(!stk.empty())
   {
      temp=stk.pop();
      cout<<temp->data<<"    ";
      temp=temp->right;
   }/*end if*/
   else
    break;
  }while(1); /*end do while*/
 }/* end if */
 else
  cout<<"
Empty tree";

} /*end function */

/*--------------------------------------------------*/
/*PREORDER RECURSIVE TRAVERSAL */
/*---------------------------------------------------*/
void binsrctree::preorder_rec(binarynode *root)
{
 if(root!=NULL)
 {
   cout<<root->data<<"    ";
   preorder_rec(root->left);
   preorder_rec(root->right);
 }
}

/*--------------------------------------------------*/
/*PREORDER NON RECURSIVE TRAVERSAL */
/*---------------------------------------------------*/

void binsrctree::preorder_non_rec(binarynode *root)
{
 stack stk;
 binarynode *temp=root;

 stk.push(temp);

 while(!stk.empty())
 {
  temp=stk.pop();
  if(temp!=NULL)
  {
   cout<<temp->data<<"    ";
   stk.push(temp->right);
   stk.push(temp->left);
  }
 }

}

/*--------------------------------------------------*/
/*POSTRDER RECURSIVE TRAVERSAL */
/*---------------------------------------------------*/

void binsrctree::postorder_rec(binarynode *root)
{
 if(root!=NULL)
 {
  postorder_rec(root->left);
  postorder_rec(root->right);
  cout<<root->data<<"    ";
 }
}

/*--------------------------------------------------*/
/*POSTORDER NON RECURSIVE TRAVERSAL */
/*---------------------------------------------------*/

void binsrctree::postorder_non_rec(binarynode *root)
{
 stack stk;
 stack_int stk1;
 int flag;
 binarynode *temp=root;

 do
 {
  if(temp!=NULL)
  {
   stk.push(temp);
   stk1.push(1);
   temp=temp->left;
  }
  else
  {
   if(stk.empty())
     break;
   temp=stk.pop();
   flag=stk1.pop();
     if(flag==2)
     {
      cout<<temp->data;
      temp=NULL;
     } /*end if */
     else
     {
      stk.push(temp);
      stk1.push(2);
      temp=temp->right;
     } /* end else */
  } /* end if */
 }while(1);/*end do while*/
}/*end function*/

/*--------------------------------------------------*/
/*FUNCTION TO PRINT INORDER RECURSIVE TRAVERSAL */
/*---------------------------------------------------*/

void binsrctree::print_inorder_rec()
{
 cout<<"
";
 inorder_rec(root);
 cout<<"
";
}

/*--------------------------------------------------*/
/*FUNCTION TO PRINT INORDER NON RECURSIVE TRAVERSAL */
/*---------------------------------------------------*/

void binsrctree::print_inorder_non_rec()
{
 cout<<"
";
 inorder_non_rec(root);
 cout<<"
";
}

/*--------------------------------------------------*/
/*FUNCTION TO PRINT PREORDER RECURSIVE TRAVERSAL */
/*---------------------------------------------------*/

void binsrctree::print_preorder_rec()
{
 cout<<"
";
 preorder_rec(root);
 cout<<"
";
}

/*--------------------------------------------------*/
/*FUNCTION TO PRINT PREORDER NON RECURSIVE TRAVERSAL */
/*---------------------------------------------------*/

void binsrctree::print_preorder_non_rec()
{
 cout<<"
";
 preorder_non_rec(root);
 cout<<"
";
}

/*--------------------------------------------------*/
/*FUNCTION TO PRINT POSTORDER RECURSIVE TRAVERSAL */
/*---------------------------------------------------*/

void binsrctree::print_postorder_rec()
{
 cout<<"
";
 postorder_rec(root);
 cout<<"
";
}

/*--------------------------------------------------*/
/*FUNCTION TO PRINT POSTORDER NON RECURSIVE TRAVERSAL */
/*---------------------------------------------------*/

void binsrctree::print_postorder_non_rec()
{
 cout<<"
";
 postorder_non_rec(root);
 cout<<"
";
}

/*--------------------------------------------------*/
/* MAIN FUNCTION */
/*---------------------------------------------------*/

void main()
{
 binsrctree BST;
 int ch,element;
 clrscr();

 do
 {
  cout<<"
1.Insert a node in binary tree";
  cout<<"
2.Recursive Inorder traversal";
  cout<<"
3.Non Recursive Inorder traversal";
  cout<<"
4.Recursive preorder traversal";
  cout<<"
5.Non recursive preorder traversal";
  cout<<"
6.Recursive postorder traversal";
  cout<<"
7.Non recursive postorder traversal";
  cout<<"
8.Exit";
  cout<<"
Enter your choice";
  cin>>ch;

  switch(ch)
  {
   case 1:
    cout<<"
Enter the element you wnat to insert";
    cin>>element;
    BST.insert(element);
    break;
   case 2:
    cout<<"
Recursive Inorder traversal
";
    BST.print_inorder_rec();
    break;
   case 3:
    cout<<"
NonRecursive Inorder traversal
";
    BST.print_inorder_non_rec();
    break;
   case 4:
    cout<<"
Recursive preorder traversal
";
    BST.print_preorder_rec();
    break;
   case 5:
    cout<<"
Non recursive preorder traversal
";
    BST.print_preorder_non_rec();
    break;
   case 6:
    cout<<"
Recursive postorder traversal";
    BST.print_postorder_rec();
    break;
   case 7:
    cout<<"
Non recursive postorder traversal
";
    BST.print_postorder_non_rec();
    break;
   case 8:
    exit(1);

  }
 }while(ch<8);
}