doubly.cpp

#include<iostream>
using namespace std;
void push(int x);

typedef struct alvi
{
    int data;

    struct alvi *next;
    struct alvi *prev;
}node;
node *head=NULL;

int main()
{
    push(1);
    push(2);
    push(3);
    return 0;
}
void push(int x)
{
    node *newNode = new node();
    newNode->data = x;
    if(head==NULL)
    {
        cout<<"First node pushed"<<endl;
        newNode->prev=NULL;
        newNode->next=NULL;
        head=newNode;
    }
    else
    {
        cout<<"other node pushed"<<endl;
        newNode->prev=NULL;
        newNode->next=head;
        head= newNode;
    }
}