#include <iostream.h>
template<class T>
class Node
{
	friend LinkedStack<T>;
	private:
	T data;
	Node<T> *link;
};
template<class T>
class LinkedStack {
	public:
		LinkedStack() {top = 0;}
		~LinkedStack();
		int IsEmpty() const {return top == 0;}
		T Top() const;
		LinkedStack<T>& Add(const T& x);
		LinkedStack<T>& Delete(T& x);
	private:
		Node<T> *top; 
};
	template<class T>
LinkedStack<T>::~LinkedStack()
{// Stack destructor..
	Node<T> *next;
	while (top) {
		next = top->link;
		delete top;
		top = next;
	}
}
template<class T>
T LinkedStack<T>::Top() const
{// Return top element.
	if (IsEmpty()) cout<<"Stack empty:";
	else
		return top->data;
}
	template<class T>
LinkedStack<T>& LinkedStack<T>::Add(const T& x)
{// Add x to stack.
	Node<T> *p = new Node<T>;
	p->data = x;
	p->link = top;
	top = p;
	return *this;
}
	template<class T>
LinkedStack<T>& LinkedStack<T>::Delete(T& x)
{// Delete top element and put it in x.
	if (IsEmpty()) 
	{
		cout<<"Stack empty";
		return *this;
	}
	x = top->data;
	Node<T> *p = top;
	top = top->link;
	delete p;
	return *this;
}
void main(void)
{
	int x;
	LinkedStack<int> S;
	S.Add(1).Add(2).Add(3).Add(4);
	cout << "Stack should be 1234" << endl;
	cout << "Stack top is " << S.Top() << endl;
	S.Delete(x);
	cout << "Deleted " << x << endl;
	S.Delete(x);
	cout << "Deleted " << x << endl;
	S.Delete(x);
	cout << "Deleted " << x << endl;
	S.Delete(x);
	cout << "Deleted " << x << endl;
}

#include<iostream.h>
#include<constream.h>
template<class T>
class Stack
{
	public:
		Stack(int MaxStackSize);
		~Stack(){delete[] S;}
		int IsEmpty()const{return top==-1;}
		int IsFull()const{return top==MaxTop;}
		T Peek()const;
		void Push(T);
		T Pop();
		void Display();
	private:
		int top; //current top of stack
		int MaxTop; //max val for top
		T *S; //element array
};
	template<class T>
Stack<T>::Stack(int MaxStackSize)
{
	//stack constructor
	MaxTop=MaxStackSize-1;
	S=new T[MaxStackSize];
	top=-1;
}
template<class T>
T Stack<T>::Peek()const
{
	if(IsEmpty()) //top fails
		return 0;
	else
		return S[top];
}
	template<class T>
void Stack<T>::Push(T x)
{
	if(IsFull())
		cout<<"no memory()"; //add fails
	else
	{
		S[++top]=x;
	}
}
	template<class T>
T Stack<T>::Pop()
{
	T x;
	if(IsEmpty())
	{
		cout<<"stack is empty\n";
		return -1;
	}
	else
	{
		x=S[top--];
		return x;
	}
}
	template<class T>
void Stack<T>::Display()
{
	if(IsEmpty())
		cout<<"out of bounds"; //delete fails
	else
		for(int i=top;i>=0;i--)
		{
			cout<<S[i]<<"\t";
		}
}
void menu()
{
	cout<<"1.Push\n 2.Pop\n 3.Peek\n 4.Display\n";
}
void main()
{
	Stack<int>iobj(5);
	int ch,x;
	clrscr();
	do
	{
		menu();
		cout<<"enter the choice\n";
		cin>>ch;
		switch(ch)
		{
			case 1:
				cout<<"enter x value to push into the stack\n";
				cin>>x;
				iobj.Push(x);
				break;
			case 2:
				x=iobj.Pop();
				if(x!=-1)
					cout<<"poped value is \t"<<x<<endl;
				break;
			case 3:
				x=iobj.Peek();
				cout<<"top most value is \t"<<x<<endl;
				break;
			case 4:
				iobj.Display();
				break;
		}
	}while(ch>=1&&ch<=4);
	getch();
}

#include <iostream.h>
class poly
{
	private :
		struct polynode
		{
			float coeff ;
			int exp ;
			polynode *link ;
		} *p ;
	public :
		poly( ) ;
		void poly_append ( float c, int e ) ;
		void display_poly( ) ;
		void poly_multiply ( poly &p1, poly &p2 ) ;
		void padd ( float c, int e ) ;
		~poly( ) ;
} ;
poly :: poly( )
{
	p = NULL ;
}
void poly :: poly_append ( float c, int e )
{
	polynode *temp ;
	temp = p ;
	if ( temp == NULL )
	{
		temp = new polynode ;
		p = temp ;
	}
	else
	{
		while ( temp -> link != NULL )
			temp = temp -> link ;
		temp -> link = new polynode ;
		temp = temp -> link ;
	}
	temp -> coeff = c ;
	temp -> exp = e ;
	temp -> link = NULL ;
}
void poly :: display_poly( )
{
	polynode *temp = p ;
	int f = 0 ;
	while ( temp != NULL )
	{
		if ( f != 0 )
		{
			if ( temp -> coeff > 0 )
				cout << " + " ;
			else
				cout << " " ;
		}
		if ( temp -> exp != 0 )
			cout << temp -> coeff << "x^" << temp -> exp ;
		else
			cout << temp -> coeff ;
		temp = temp -> link ;
		f = 1 ;
	}
}
void poly :: poly_multiply ( poly &p1, poly &p2 )
{
	polynode *temp1, *temp2 ;
	float coeff1, exp1 ;
	temp1 = p1.p ;
	temp2 = p2.p ;
	if ( temp1 == NULL && temp2 == NULL )
		return ;
	if ( temp1 == NULL )
		p = p2.p ;
	else
	{
		if ( temp2 == NULL )
			p = temp1 ;
		else		{
			while ( temp1 != NULL )
			{
				while ( temp2 != NULL )
				{
					coeff1 = temp1 -> coeff * temp2 -> coeff ;
					exp1 = temp1 -> exp + temp2 -> exp ;
					temp2 = temp2 -> link ;
					padd ( coeff1, exp1 ) ;
				}
				temp2 = p2.p ;
				temp1 = temp1 -> link ;
			}
		}
	}
}
void poly :: padd ( float c, int e )
{
	polynode *r, *temp ;
	temp = p ;
	if ( temp == NULL || c > temp -> exp )
	{
		r = new polynode ;
		r -> coeff = c ;
		r -> exp = e ;
		if ( p == NULL )
		{
			r -> link = NULL ;
			p = r ;
		}
		else
		{
			r -> link = temp ;
			p = r ;
		}
	}
	else
	{
		while ( temp != NULL )
		{
			if ( temp -> exp == e )
			{
				temp -> coeff += c ;
				return ;
			}
			if ( temp -> exp > c && ( temp -> link -> exp < c ||
						temp -> link == NULL ) )
			{
				r = new polynode ;
				r -> coeff = c;
				r -> exp = e ;
				r -> link = NULL ;
				temp -> link = r ;
				return ;
			}
			temp = temp -> link ;
		}
		r -> link = NULL ;
		temp -> link = r ;
	}
}
poly :: ~poly( )
{
	polynode *q ;
	while ( p != NULL )
	{
		q = p -> link ;
		delete p ;
		p = q ;
	}
}
void main( )
{
	poly p1 ;
	p1.poly_append ( 3, 5 ) ;
	p1.poly_append ( 2, 4 ) ;
	p1.poly_append ( 1, 2 ) ;
 
	cout << "\nFirst polynomial: " << endl ;
	p1.display_poly( ) ;
	poly p2 ;
	p2.poly_append ( 1, 6 ) ;
	p2.poly_append ( 2, 5 ) ;
	p2.poly_append ( 3, 4 ) ;
	cout << "\nSecond polynomial: " << endl ;
	p2.display_poly( ) ;
	poly p3 ;
	p3.poly_multiply ( p1, p2 ) ;
	cout << "\nResultant polynomial: " << endl ;
	p3.display_poly( ) ;
}

#include <iostream.h>
class poly
{
	private :
		struct polynode
		{
			float coeff ;
			int exp ;
			polynode *link ;
		} *p ;
	public :
		poly( ) ;
		void poly_append ( float c, int e ) ;
		void display_poly( ) ;
		void poly_add( poly &l1, poly &l2 ) ;
		~poly( ) ;
} ;
poly :: poly( )
{
	p = NULL ;
}
void poly :: poly_append ( float c, int e )
{
	polynode *temp = p ;
	if ( temp == NULL )
	{
		temp = new polynode ;
		p = temp ;
	}
	else
	{
		while ( temp -> link != NULL )
			temp = temp -> link ;
		temp -> link = new polynode ;
		temp = temp -> link ;
	}
	temp -> coeff = c ;
	temp -> exp = e ;
	temp -> link = NULL ;
}
void poly :: display_poly( )
{
	polynode *temp = p ;
	int f = 0 ;
 
	cout << endl ;
	while ( temp != NULL )
	{
		if ( f != 0 )
		{
			if ( temp -> coeff > 0 )
				cout << " + " ;
			else
				cout << " " ;
		}
		if ( temp -> exp != 0 )
			cout << temp -> coeff << "x^" << temp -> exp ;
		else
			cout << temp -> coeff ;
		temp = temp -> link ;
		f = 1 ;
	}
}
void poly :: poly_add ( poly &l1, poly &l2 )
{
	polynode *z ;
	if ( l1.p == NULL && l2.p == NULL )
		return ;
	polynode *temp1, *temp2 ;
	temp1 = l1.p ;
	temp2 = l2.p ;
	while ( temp1 != NULL && temp2 != NULL )
	{
		if ( p == NULL )
		{
			p = new polynode ;
			z = p ;
		}
		else
		{
			z -> link = new polynode ;
			z = z -> link ;
		}
		if ( temp1 -> exp < temp2 -> exp )
		{
			z -> coeff = temp2 -> coeff ;
			z -> exp = temp2 -> exp ;
			temp2 = temp2 -> link ;
		}
		else
		{
			if ( temp1 -> exp > temp2 -> exp )
			{
				z -> coeff = temp1 -> coeff ;
				z -> exp = temp1 -> exp ;
				temp1 = temp1 -> link ;
			}
			else
			{
				if ( temp1 -> exp == temp2 -> exp )
				{
					z -> coeff = temp1 -> coeff + temp2 -> coeff ;
					z -> exp = temp1 -> exp ;
					temp1 = temp1 -> link ;
					temp2 = temp2 -> link ;
				}
			}
		}
	}
	while ( temp1 != NULL )
	{
		if ( p == NULL )
		{
			p = new polynode ;
			z = p ;
		}
		else
		{
			z -> link = new polynode ;
			z = z -> link ;
		}
		z -> coeff = temp1 -> coeff ;
		z -> exp = temp1 -> exp ;
		temp1 = temp1 -> link ;
	}
	while ( temp2 != NULL )
	{
		if ( p == NULL )
		{
			p = new polynode ;
			z = p ;
		}
		else
		{
			z -> link = new  polynode ;
			z = z -> link ;
		}
		z -> coeff = temp2 -> coeff ;
		z -> exp = temp2 -> exp ;
		temp2 = temp2 -> link ;
	}
	z -> link = NULL ;
}
poly :: ~poly( )
{
	polynode *q ;
	while ( p != NULL )
	{
		q = p -> link ;
		delete p ;
		p = q ;
	}
}
void main( )
{
	poly p1 ;
	p1.poly_append ( 1.4, 5 ) ;
	p1.poly_append ( 1.5, 4 ) ;
	p1.poly_append ( 1.7, 2 ) ;
	p1.poly_append ( 1.8, 1 ) ;
	p1.poly_append ( 1.9, 0 ) ;
	cout << "\nFirst polynomial:" ;
	p1.display_poly( ) ;
	poly p2 ;
	p2.poly_append ( 1.5, 6 ) ;
	p2.poly_append ( 2.5, 5 ) ;
	p2.poly_append ( -3.5, 4 ) ;
	p2.poly_append ( 4.5, 3 ) ;
	p2.poly_append ( 6.5, 1 ) ;
	cout << "\nSecond polynomial:" ;
	p2.display_poly( ) ;
	poly p3 ;
	p3.poly_add ( p1, p2 ) ;
	cout << "\nResultant polynomial: " ;
	p3.display_poly( ) ;
}

#include <iostream.h>
#include <stdlib.h>
#include <alloc.h>
const int MAX = 4 ;
const int MIN = 2 ;
struct btnode
{
	int count ;
	int value[MAX + 1] ;
	btnode *child[MAX + 1] ;
} ;
class btree
{
	private :
		btnode *root ;
	public :
		btree( ) ;
		void insert ( int val ) ;
		int setval ( int val, btnode *n, int *p, btnode **c ) ;
		static btnode * search ( int val, btnode *root, int *pos ) ;
		static int searchnode ( int val, btnode *n, int *pos ) ;
		void fillnode ( int val, btnode *c, btnode *n, int k ) ;
		void split ( int val, btnode *c, btnode *n,
				int k, int *y, btnode **newnode ) ;
		void del ( int val ) ;
		int delhelp ( int val, btnode *root ) ;
		void clear ( btnode *root, int k ) ;
		void copysucc ( btnode *root, int i ) ;
		void restore ( btnode *root, int i ) ;
		void rightshift ( int k ) ;
		void leftshift ( int k ) ;
		void merge ( int k ) ;
		void show( ) ;
		static void display ( btnode *root ) ;
		static void deltree ( btnode *root ) ;
		~btree( ) ;
} ;
 
btree :: btree( )
{
	root = NULL ;
}
void btree :: insert ( int val )
{
	int i ;
	btnode *c, *n ;
	int flag ;
	flag = setval ( val, root, &i, &c ) ;
	if ( flag )
	{
		n = new btnode ;
		n -> count = 1 ;
		n -> value[1] = i ;
		n -> child[0] = root ;
		n -> child[1] = c ;
		root = n ;
	}
}
int btree :: setval ( int val, btnode *n, int *p, btnode **c )
{
	int k ;
	if ( n == NULL )
	{
		*p = val ;
		*c = NULL ;
		return 1 ;
	}
	else
	{
		if ( searchnode ( val, n, &k ) )
			cout << endl << "Key value already exists." << endl ;
		if ( setval ( val, n -> child[k], p, c ) )
		{
			if ( n -> count < MAX )
			{
				fillnode ( *p, *c, n, k ) ;
				return 0 ;
			}
			else
			{
				split ( *p, *c, n, k, p, c ) ;
				return 1 ;
			}
		}
		return 0 ;
	}
}
btnode * btree :: search ( int val, btnode *root, int *pos )
{
	if ( root == NULL )
		return NULL ;
	else
	{
		if ( searchnode ( val, root, pos ) )
			return root ;
		else
			return search ( val, root -> child[*pos], pos ) ;
	}
}
int btree :: searchnode ( int val, btnode *n, int *pos )
{
	if ( val < n -> value[1] )
	{
		*pos = 0 ;
		return 0 ;
	}
	else
	{
		*pos = n -> count ;
		while ( ( val < n -> value[*pos] ) && *pos > 1 )
			( *pos )-- ;
		if ( val == n -> value[*pos] )
			return 1 ;
		else
			return 0 ;
	}
}
void btree :: fillnode ( int val, btnode *c, btnode *n, int k )
{
	int i ;
	for ( i = n -> count ; i > k ; i-- )
	{
		n -> value[i + 1] = n -> value[i] ;
		n -> child[i + 1] = n -> child[i] ;
	}
	n -> value[k + 1] = val ;
	n -> child[k + 1] = c ;
	n -> count++ ;
}
void btree :: split ( int val, btnode *c, btnode *n,
		int k, int *y, btnode **newnode )
{
	int i, mid ;
 
	if ( k <= MIN )
		mid = MIN ;
	else
		mid = MIN + 1 ;
 
	*newnode = new btnode ;
 
	for ( i = mid + 1 ; i <= MAX ; i++ )
	{
		( *newnode ) -> value[i - mid] = n -> value[i] ;
		( *newnode ) -> child[i - mid] = n -> child[i] ;
	}
 
	( *newnode ) -> count = MAX - mid ;
	n -> count = mid ;
 
	if ( k <= MIN )
		fillnode ( val, c, n, k ) ;
	else
		fillnode ( val, c, *newnode, k - mid ) ;
 
	*y = n -> value[n -> count] ;
	( *newnode ) -> child[0] = n -> child[n -> count] ;
	n -> count-- ;
}
void btree :: del ( int val )
{
	btnode * temp ;
 
	if ( ! delhelp ( val, root ) )
		cout << endl << "Value " << val << " not found." ;
	else
	{
		if ( root -> count == 0 )
		{
			temp = root ;
			root = root -> child[0] ;
			delete temp ;
		}
	}
}
int btree :: delhelp ( int val, btnode *root )
{
	int i ;
	int flag ;
 
	if ( root == NULL )
		return 0 ;
	else
	{
		flag = searchnode ( val, root, &i ) ;
		if ( flag )
		{
			if ( root -> child[i - 1] )
			{
				copysucc ( root, i ) ;
				flag = delhelp ( root -> value[i], root -> child[i] ) ;
				if ( !flag )
					cout << endl << "Value " << val << " not found." ;
			}
			else
				clear ( root, i ) ;
		}
		else
			flag = delhelp ( val, root -> child[i] ) ;
		if ( root -> child[i] != NULL )
		{
			if ( root -> child[i] -> count < MIN )
				restore ( root, i ) ;
		}
		return flag ;
	}
}
void btree :: clear ( btnode *root, int k )
{
	int i ;
	for ( i = k + 1 ; i <= root -> count ; i++ )
	{
		root -> value[i - 1] = root -> value[i] ;
		root -> child[i - 1] = root -> child[i] ;
	}
	root -> count-- ;
}
void btree :: copysucc ( btnode *root, int i )
{
	btnode *temp = root -> child[i] ;
 
	while ( temp -> child[0] )
		temp = temp -> child[0] ;
 
	root -> value[i] = temp -> value[1] ;
}
void btree :: restore ( btnode *root, int i )
{
	if ( i == 0 )
	{
		if ( root -> child [1] -> count > MIN )
			leftshift ( 1 ) ;
		else
			merge ( 1 ) ;
	}
	else
	{
		if ( i == root -> count )
		{
			if ( root -> child[i - 1] -> count > MIN )
				rightshift ( i ) ;
			else
				merge ( i ) ;
		}
		else
		{
			if ( root -> child[i - 1] -> count > MIN )
				rightshift ( i ) ;
			else
			{
				if ( root -> child[i + 1] -> count > MIN )
					leftshift ( i + 1 ) ;
				else
					merge ( i ) ;
			}
		}
	}
}
void btree :: rightshift ( int k )
{
	int i ;
	btnode *temp ;
 
	temp = root -> child[k] ;
 
	for ( i = temp -> count ; i > 0 ; i-- )
	{
		temp -> value[i + 1] = temp -> value[i] ;
		temp -> child[i + 1] = temp -> child[i] ;
	}
 
	temp -> child[1] = temp -> child[0] ;
	temp -> count++ ;
	temp -> value[1] = root -> value[k] ;
	temp = root -> child[k - 1] ;
	root -> value[k] = temp -> value[temp -> count] ;
	root -> child[k] -> child [0] = temp -> child[temp -> count] ;
	temp -> count-- ;
}
void btree :: leftshift ( int k )
{
	btnode *temp ;
 
	temp = root -> child[k - 1] ;
	temp -> count++ ;
	temp -> value[temp -> count] = root -> value[k] ;
	temp -> child[temp -> count] = root -> child[k] -> child[0] ;
	temp = root -> child[k] ;
	root -> value[k] = temp -> value[1] ;
	temp -> child[0] = temp -> child[1] ;
	temp -> count-- ;
	for ( int i = 1 ; i <= temp -> count ; i++ )
	{
		temp -> value[i] = temp -> value[i + 1] ;
		temp -> child[i] = temp -> child[i + 1] ;
	}
}
void btree :: merge ( int k )
{
	btnode *temp1, *temp2 ;
	temp1 = root -> child[k] ;
	temp2 = root -> child[k - 1] ;
	temp2 -> count++ ;
	temp2 -> value[temp2 -> count] = root -> value[k] ;
	temp2 -> child[temp2 -> count] = root -> child[0] ;
	for ( int i = 1 ; i <= temp1 -> count ; i++ )
	{
		temp2 -> count++ ;
		temp2 -> value[temp2 -> count] = temp1 -> value[i] ;
		temp2 -> child[temp2 -> count] = temp1 -> child[i] ;
	}
	for ( i = k ; i < root -> count ; i++ )
	{
		root -> value[i] = root -> value[i + 1] ;
		root -> child[i] = root -> child[i + 1] ;
	}
	root -> count-- ;
	delete temp1 ;
}
void btree :: show( )
{
	display ( root ) ;
}
void btree :: display ( btnode *root )
{
	if ( root != NULL )
	{
		for ( int i = 0 ; i < root -> count ; i++ )
		{
			display ( root -> child[i] ) ;
			cout << root -> value[i + 1] << "\t" ;
		}
		display ( root -> child[i] ) ;
	}
}
void btree :: deltree ( btnode *root )
{
	if ( root != NULL )
	{
		for ( int i = 0 ; i < root -> count ; i++ )
		{
			deltree ( root -> child[i] ) ;
			delete ( root -> child[i] ) ;
		}
		deltree ( root -> child[i] ) ;
		delete ( root -> child[i] ) ;
	}
}
 
btree :: ~btree( )
{
	deltree ( root ) ;
}
 
void main( )
{
	btree b ;
	int arr[ ] = { 27, 42, 22, 47, 32, 2, 51, 40, 13 } ;
	int sz = sizeof ( arr ) / sizeof ( int ) ;
	for ( int i = 0 ; i < sz ; i++ )
		b.insert ( arr[i] ) ;
	cout << "B-tree of order 5:" << endl ;
	b.show( ) ;
	b.del ( 22 ) ;
	b.del ( 11 ) ;
	cout << "\n\nB-tree after deletion of values:" << endl ;
	b.show( ) ;
}

#include <iostream.h>
#include <stdlib.h>
#include<constream.h>
#define FALSE 0
#define TRUE 1
struct AVLNode
{
	int data ;
	int balfact ;
	AVLNode *left ;
	AVLNode *right ;
} ;
 
class avltree
{
	private :
		AVLNode *root ;
	public :
		avltree( ) ;
		AVLNode*  insert ( int data, int *h ) ;
		static AVLNode* buildtree ( AVLNode *root, int data, int *h ) ;
		void display( AVLNode *root ) ;
		AVLNode* deldata ( AVLNode* root, int data, int *h ) ;
		static AVLNode* del ( AVLNode *node, AVLNode* root, int *h ) ;
		static AVLNode* balright ( AVLNode *root, int *h ) ;
		static AVLNode* balleft ( AVLNode* root, int *h ) ;
		void setroot ( AVLNode *avl ) ;
		~avltree( ) ;
		static void deltree ( AVLNode *root ) ;
} ;
avltree :: avltree( )
{
	root = NULL ;
}
AVLNode* avltree :: insert ( int data, int *h )
{
	root = buildtree ( root, data, h ) ;
	return root ;
}
AVLNode* avltree :: buildtree ( AVLNode *root, int data, int *h )
{
	AVLNode *node1, *node2 ;
 
	if ( root == NULL )
	{
		root = new AVLNode ;
		root -> data = data ;
		root -> left = NULL ;
		root -> right = NULL ;
		root -> balfact = 0 ;
		*h = TRUE ;
		return ( root ) ;
	}
	if ( data < root -> data )
	{
		root -> left = buildtree ( root -> left, data, h ) ;
 
		// If left subtree is higher
		if ( *h )
		{
			switch ( root -> balfact )
			{
				case 1 :
					node1 = root -> left ;
					if ( node1 -> balfact == 1 )
					{
						cout << "\nRight rotation." ;
						root -> left = node1 -> right ;
						node1 -> right = root ;
						root -> balfact = 0 ;
						root = node1 ;
					}
					else
					{
						cout << "\nDouble rotation, left then right." ;
						node2 = node1 -> right ;
						node1 -> right = node2 -> left ;
						node2 -> left = node1 ;
						root -> left = node2 -> right ;
						node2 -> right = root ;
						if ( node2 -> balfact == 1 )
							root -> balfact = -1 ;
						else
							root -> balfact = 0 ;
						if ( node2 -> balfact == -1 )
							node1 -> balfact = 1 ;
						else
							node1 -> balfact = 0 ;
						root = node2 ;
					}
					root -> balfact = 0 ;
					*h = FALSE ;
					break ;
 
				case 0 :
					root -> balfact = 1 ;
					break ;
				case -1 :
					root -> balfact = 0 ;
					*h = FALSE ;
			}
		}
	}
 
	if ( data > root -> data )
	{
		root -> right = buildtree ( root -> right, data, h ) ;
 
		if ( *h )
		{
			switch ( root -> balfact )
			{
				case 1 :
					root -> balfact = 0 ;
					*h = FALSE ;
					break ;
				case 0 :
					root -> balfact = -1 ;
					break ;
				case -1 :
					node1 = root -> right ;
					if ( node1 -> balfact == -1 )
					{
						cout << "\nLeft rotation." ;
						root -> right = node1 -> left ;
						node1 -> left = root ;
						root -> balfact = 0 ;
						root = node1 ;
					}
					else
					{
						cout << "\nDouble rotation, right then left." ;
						node2 = node1 -> left ;
						node1 -> left = node2 -> right ;
						node2 -> right = node1 ;
						root -> right = node2 -> left ;
						node2 -> left = root ;
						if ( node2 -> balfact == -1 )
							root -> balfact = 1 ;
						else
							root -> balfact = 0 ;
						if ( node2 -> balfact == 1 )
							node1 -> balfact = -1 ;
						else
							node1 -> balfact = 0 ;
						root = node2 ;
					}
					root -> balfact = 0 ;
					*h = FALSE ;
			}
		}
	}
	return ( root ) ;
}
void avltree :: display ( AVLNode* root )
{
	if ( root != NULL )
	{
		display ( root -> left ) ;
		cout << root -> data << "\t" ;
		display ( root -> right ) ;
	}
}
AVLNode* avltree :: deldata ( AVLNode *root, int data, int *h )
{
	AVLNode *node ;
	if ( root -> data == 13 )
		cout << root -> data ;
	if ( root == NULL )
	{
		cout << "\nNo such data." ;
		return ( root ) ;
	}
	else
	{
		if ( data < root -> data )
		{
			root -> left = deldata ( root -> left, data, h ) ;
			if ( *h )
				root = balright ( root, h ) ;
		}
		else
		{
			if ( data > root -> data )
			{
				root -> right = deldata ( root -> right, data, h ) ;
				if ( *h )
					root = balleft ( root, h ) ;
			}
			else
			{
				node = root ;
				if ( node -> right == NULL )
				{
					root = node -> left ;
					*h = TRUE ;
					delete ( node ) ;
				}
				else
				{
					if ( node -> left == NULL )
					{
						root = node -> right ;
						*h = TRUE ;
						delete ( node ) ;
					}
					else
					{
						node -> right = del ( node -> right, node, h ) ;
						if ( *h )
							root = balleft ( root, h ) ;
					}
				}
			}
		}
	}
	return ( root ) ;
}
AVLNode* avltree :: del ( AVLNode *succ, AVLNode *node, int *h )
{
	AVLNode *temp = succ ;
 
	if ( succ -> left != NULL )
	{
		succ -> left = del ( succ -> left, node, h ) ;
		if ( *h )
			succ = balright ( succ, h ) ;
	}
	else
	{
		temp = succ ;
		node -> data = succ -> data ;
		succ = succ -> right ;
		delete ( temp ) ;
		*h = TRUE ;
	}
	return ( succ ) ;
}
AVLNode* avltree :: balright ( AVLNode *root, int *h )
{
	AVLNode *temp1, *temp2 ;
	switch ( root -> balfact )
	{
		case 1 :
			root -> balfact = 0 ;
			break ;
		case 0 :
			root -> balfact = -1 ;
			*h  = FALSE ;
			break ;
		case -1 :
			temp1 = root -> right ;
			if ( temp1 -> balfact <= 0 )
			{
				cout << "\nLeft rotation." ;
				root -> right = temp1 -> left ;
				temp1 -> left = root ;
				if ( temp1 -> balfact == 0 )
				{
					root -> balfact = -1 ;
					temp1 -> balfact = 1 ;
					*h = FALSE ;
				}
				else
				{
					root -> balfact = temp1 -> balfact = 0 ;
				}
				root = temp1 ;
			}
			else
			{
				cout << "\nDouble rotation, right then left." ;
				temp2 = temp1 -> left ;
				temp1 -> left = temp2 -> right ;
				temp2 -> right = temp1 ;
				root -> right = temp2 -> left ;
				temp2 -> left = root ;
				if ( temp2 -> balfact == -1 )
					root -> balfact = 1 ;
				else
					root -> balfact = 0 ;
				if ( temp2 -> balfact == 1 )
					temp1 -> balfact = -1 ;
				else
					temp1 -> balfact = 0 ;
				root = temp2 ;
				temp2 -> balfact = 0 ;
			}
	}
	return ( root ) ;
}
AVLNode* avltree :: balleft ( AVLNode *root, int *h )
{
	AVLNode *temp1, *temp2 ;
	switch ( root -> balfact )
	{
		case -1 :
			root -> balfact = 0 ;
			break ;
 
		case 0 :
			root -> balfact = 1 ;
			*h = FALSE ;
			break ;
 
		case 1 :
			temp1 = root -> left ;
			if ( temp1 -> balfact >= 0 )
			{
				cout << "\nRight rotation." ;
				root -> left = temp1 -> right ;
				temp1 -> right = root ;
 
				if ( temp1 -> balfact == 0 )
				{
					root -> balfact = 1 ;
					temp1 -> balfact = -1 ;
					*h = FALSE ;
				}
				else
				{
					root -> balfact = temp1 -> balfact = 0 ;
				}
				root = temp1 ;
			}
			else
			{
				cout << "\nDouble rotation, left then right." ;
				temp2 = temp1 -> right ;
				temp1 -> right = temp2 -> left ;
				temp2 -> left = temp1 ;
				root -> left = temp2 -> right ;
				temp2 -> right = root ;
				if ( temp2 -> balfact == 1 )
					root -> balfact = -1 ;
				else
					root -> balfact = 0 ;
				if ( temp2-> balfact == -1 )
					temp1 -> balfact = 1 ;
				else
					temp1 -> balfact = 0 ;
				root = temp2 ;
				temp2 -> balfact = 0 ;
			}
	}
	return ( root ) ;
}
void avltree :: setroot ( AVLNode *avl )
{
	root = avl ;
}
avltree :: ~avltree( )
{
	deltree ( root ) ;
}
 
 
void avltree :: deltree ( AVLNode *root )
{
	if ( root != NULL )
	{
		deltree ( root -> left ) ;
		deltree ( root -> right ) ;
	}
	delete ( root ) ;
}
void main( )
{
	avltree at ;
	AVLNode *avl = NULL ;
	int h ;
	clrscr();
	avl = at.insert ( 20, &h ) ;
	at.setroot ( avl ) ;
	avl = at.insert ( 6, &h ) ;
	at.setroot ( avl ) ;
	avl = at.insert ( 29, &h ) ;
	at.setroot ( avl ) ;
	avl = at.insert ( 5, &h ) ;
	at.setroot ( avl ) ;
	avl = at.insert ( 12, &h ) ;
	at.setroot ( avl ) ;
	avl = at.insert ( 25, &h ) ;
	at.setroot ( avl ) ;
	avl = at.insert ( 32, &h ) ;
	at.setroot ( avl ) ;
	avl = at.insert ( 10, &h ) ;
	at.setroot ( avl ) ;
	avl = at.insert ( 15, &h ) ;
	at.setroot ( avl ) ;
	avl = at.insert ( 27, &h ) ;
	at.setroot ( avl ) ;
	avl = at.insert ( 13, &h ) ;
	at.setroot ( avl ) ;
	cout << endl << "AVL tree:\n" ;
	at.display ( avl ) ;
	avl = at.deldata ( avl, 20, &h ) ;
	at.setroot ( avl ) ;
	avl = at.deldata ( avl, 12, &h ) ;
	at.setroot ( avl ) ;
	cout << endl << "AVL tree after deletion of a node:\n" ;
	at.display ( avl ) ;
	getch();
}

#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( ) ;
}

#include<iostream.h>
#include<conio.h>
#include<process.h>
struct tree_node
{
	tree_node *left;
	tree_node *right;
	int data;
} ;
class bst
{
	tree_node *root;
	public:
	bst()
	{
		root=NULL;
	}
	int isempty() 
	{
		return(root==NULL);
	}
	void insert(int item);
	void inordertrav();
	void inorder(tree_node *);
	void postordertrav();
	void postorder(tree_node *);
	void preordertrav();
	void preorder(tree_node *);
};
void bst::insert(int item)
{
	tree_node *p=new tree_node;
	tree_node *parent;
	p->data=item;
	p->left=NULL;
	p->right=NULL;
	parent=NULL;
	if(isempty())
		root=p;
	else
	{
		tree_node *ptr;
		ptr=root;
		while(ptr!=NULL)
		{
			parent=ptr;
			if(item>ptr->data)		
				ptr=ptr->right;
			else
				ptr=ptr->left;
		}	
		if(item<parent->data)
			parent->left=p;
		else
			parent->right=p;
	}
}
void bst::inordertrav()
{
	inorder(root);
}
void bst::inorder(tree_node *ptr)
{
	if(ptr!=NULL)
	{
		inorder(ptr->left);
		cout<<"  "<<ptr->data<<"     ";
		inorder(ptr->right);
	}
}
void bst::postordertrav()
{
	postorder(root);
}
void bst::postorder(tree_node *ptr)
{
	if(ptr!=NULL)
	{
		postorder(ptr->left);
		postorder(ptr->right);
		cout<<"  "<<ptr->data<<"     ";
	}
}
void bst::preordertrav()
{
	preorder(root);
}
void bst::preorder(tree_node *ptr)
{
	if(ptr!=NULL)
	{
		cout<<"  "<<ptr->data<<"     ";
		preorder(ptr->left);
		preorder(ptr->right);
	}
}
void main()
{
	bst b;
	b.insert(52);
	b.insert(25);
	b.insert(50);
	b.insert(15);
	b.insert(40);
	b.insert(45);
	b.insert(20); cout<<"inorder"<<endl;
	b.inordertrav();
	cout<<endl<<"postorder"<<endl;
	b.postordertrav();
	cout<<endl<<"preorder"<<endl;
	b.preordertrav();
	getch();
}

#include <iostream.h>
class cqueue
{
	private :
		int *arr ;
		int front, rear ;
		int MAX;
	public :
		cqueue( int maxsize = 10 ) ;
		void addq ( int item ) ;
		int delq( ) ;
		void display( ) ;
} ;
cqueue :: cqueue( int maxsize )
{
	MAX = maxsize ;
	arr = new int [ MAX ];
	front = rear = -1 ;
	for ( int i = 0 ; i < MAX ; i++ )
		arr[i] = 0 ;
}
void cqueue :: addq ( int item )
{
	if ( ( rear + 1 ) % MAX == front )
	{
		cout << "\nQueue is full" ;
		return ;
	}
	rear = ( rear + 1 ) % MAX;
	arr[rear] = item ;
	if ( front == -1 )
		front = 0 ;
}
int cqueue :: delq( )
{
	int data ;
	if ( front == -1 )
	{
		cout << "\nQueue is empty" ;
		return NULL ;
	}
 
	data = arr[front] ;
	arr[front] = 0 ;
	if ( front == rear )
	{
		front = -1 ;
		rear = -1 ;
	}
	else
		front = ( front + 1 ) % MAX;
	return data ;
}
void cqueue :: display( )
{
	cout << endl ;
	for ( int i = 0 ; i < MAX ; i++ )
		cout << arr[i] << "  " ;
	cout << endl ;
}
void main( )
{
	cqueue a ( 10 ) ;
	a.addq ( 14 ) ;
	a.addq ( 22 ) ;
	a.addq ( 13 ) ;
	a.addq ( -6 ) ;
	a.addq ( 25 ) ;
	cout << "\nElements in the circular queue: " ;
	a.display( ) ;
	int i = a.delq( ) ;
	cout << "Item deleted: " << i ;
	i = a.delq( ) ;
	cout << "\nItem deleted: " << i ;
	cout << "\nElements in the circular queue after deletion: " ;
	a.display( ) ;
	a.addq ( 21 ) ;
	a.addq ( 17 ) ;
	a.addq ( 18 ) ;
	a.addq ( 9 ) ;
	a.addq ( 20 ) ;
	cout << "Elements in the circular queue after addition: " ;
	a.display( ) ;
	a.addq ( 32 ) ;
	cout << "Elements in the circular queue after addition: " ;
	a.display( ) ;
}

#include <iostream.h>
const int MAX = 10 ;
class array
{
	private :
		int arr[MAX] ;
		int count ;
	public :
		array( ) ;
		void add ( int num ) ;
		void makeheap(int ) ;
		void heapsort( ) ;
		void display( ) ;
} ;
array :: array( )
{
	count = 0 ;
	for ( int i = 0 ; i < MAX ; i++ )
		arr[MAX] = 0 ;
}
void array :: add ( int num )
{
	if ( count < MAX )
	{
		arr[count] = num ;
		count++ ;
	}
	else
		cout << "\nArray is full" << endl ;
}
void array :: makeheap(int c)
{
 
	for ( int i = 1 ; i < c ; i++ )
	{
		int val = arr[i] ;
		int s = i ;
		int f = ( s - 1 ) / 2 ;
		while ( s > 0 && arr[f] < val )
		{
			arr[s] = arr[f] ;
			s = f ;
			f = ( s - 1 ) / 2 ;
		}
		arr[s] = val ;
	}
}
void array :: heapsort( )
{
	for ( int i = count - 1 ; i > 0 ; i-- )
	{
		int ivalue = arr[i] ;
		arr[i] = arr[0] ;
		arr[0]=ivalue;
		makeheap(i);
 
	}
}
void array :: display( )
{
	for ( int i = 0 ; i < count ; i++ )
		cout << arr[i] << "\t" ;
	cout << endl ;
}
void main( )
{
	array a ;
 
	a.add ( 11 ) ;
	a.add ( 2 ) ;
	a.add ( 9 ) ;
	a.add ( 13 ) ;
	a.add ( 57 ) ;
	a.add ( 25 ) ;
	a.add ( 17 ) ;
	a.add ( 1 ) ;
	a.add ( 90 ) ;
	a.add ( 3  ) ;
	a.makeheap(10) ;
	cout << "\nHeap Sort.\n" ;
	cout << "\nBefore Sorting:\n"  ;
	a.display( ) ;
	a.heapsort( ) ;
	cout << "\nAfter Sorting:\n" ;
	a.display( ) ;
}