#include <iostream>
#include <conio.h>
#include <cstdlib>
#include <iomanip>
using namespace std;
void initialize(int [],int ,int );
void print(int [],int );
void addelementfirst(int * & ,int & );
void addelementlast(int * & ,int & );
int *deletefirst(int [] ,int & );
int *deletelast(int [] ,int & );
int main() {
	
	int n;
	cout<<"Enter list size:";
	cin>>n;
	
	int *a=new int[n];
	initialize(a,n,0);
	cout<<endl<<"array a:";
	print(a,n);
	
	
	 addelementfirst(a,n);
	 
	 	cout<<endl<<"(add first)array a:";
	print(a,n);
	
	
     addelementlast(a,n);
     
     	cout<<endl<<"(add last)array a:";
	print(a,n);
	

	 a=deletefirst(a,n);
     
     	cout<<endl<<"(delete first)array a:";
	print(a,n);
	
	
     a=deletelast(a, n ) ;
     
     	cout<<endl<<"(delete last)array a:";
	print(a,n);
	


	
	
	
	getch();
	return 0;
}

void initialize(int a[],int n ,int v)
{
	for(int i=0;i<n;i++)
	   a[i]=v;
}
void print(int a[],int n)
{
	cout<<"  [";
	for(int i=0;i<n;i++)
	 cout<<setw(3)<<a[i];
	cout<<"  ]"<<endl; 
}
void addelementfirst(int * &a ,int &n )
{   int v;
	cout<<"enter number for add to first=";
	cin>>v;
	int *newa=new int[n+1];
	
	  if( newa==NULL){  cout<<"memory allocation error for add element!"; exit(-1);
	  }
	
	 for(int i=0;i<n;i++)
	   newa[i+1]=a[i];
	 newa[0]=v;
	  if(n) 
	  delete []a; 
     n++;
     a=newa;
}
void addelementlast(int * &a ,int &n )
{   int v;
	cout<<"enter number for add to last=";
	cin>>v;
	int *newa=new int[n+1];
	
	  if( newa==NULL){  cout<<"memory allocation error for add element!"; exit(-1);
	  }
	
	 for(int i=0;i<n;i++)
	   newa[i]=a[i];
	 newa[n]=v;
	  if(n) 
	  delete []a; 
     n++;
     a=newa;
}
int* deletefirst(int a[] ,int & n )
{
    if (n<=1 )  {   if(n) delete a;    n=0;  return NULL;   }	
     int *p=new int[n-1];
    if( p==0){  cout<<"memory allocation error for add element!"; exit(-1); }
     
    for(int i=0;i<(n-1) ;i++)
	   p[i]=a[i+1];
	delete []a;
	--n;
	return p;
 }
 
 
int *deletelast(int a[] ,int  &n )
{
   if(n<=1)  {   if(n) delete a;    n=0; a=NULL; exit(-1);    }	
    int *p=new int[n-1];
	 for(int i=0;i<n-1;i++)
	  p[i]=a[i];
	             
    delete a;
	--n;
	a=p; 
	return a;             
}