#include<stdio.h>
struct node
{
    struct node *prev;
    int value;
    struct node *next;
}*head,*last;

void insert_first(int data)
{
    struct node *newitem,*temp;
    newitem=(struct node*)malloc(sizeof(struct node));
    temp=(struct node*)malloc(sizeof(struct node));
    newitem->prev=NULL;
    newitem->value=data;
    newitem->next=NULL;
    if(head==NULL)
    {
        head=newitem;
        head->prev=NULL;
        head->next=NULL;
        last=newitem;
    }
    else
    {
        temp=newitem;
        temp->prev=NULL;
        temp->next=head;
        head->prev=temp;
        head=temp;
    }

}
void insert_last(int data)
{
    struct node *newitem,*temp;
    newitem=(struct node*)malloc(sizeof(struct node));
    temp=(struct node*)malloc(sizeof(struct node));
    newitem->prev=NULL;
    newitem->value=data;
    newitem->next=NULL;
    if(head==NULL)
    {
        head=newitem;
        head->prev=NULL;
        head->next=NULL;
        last=newitem;
    }
    else
    {
        temp=head;
        while(temp->next!=NULL)
        {
            temp=temp->next;
        }
        temp->next=newitem;
        newitem->prev=temp;
        last=newitem;
    }

}
void insert_middle(int data,int ioc)
{

}
void deleteitem(int data)
{

}
void display()
{
    struct node *temp;
    temp=(struct node*)malloc(sizeof(struct node));
    temp=head;
    while(temp!=NULL)
    {
        printf("%d ",temp->value);
        temp=temp->next;
    }
    printf("\n");
}
int count()
{
    int c=0;
    struct node *temp;
    temp=(struct node*)malloc(sizeof(struct node));
    temp=head;
    while(temp!=NULL)
    {
        c++;
        temp=temp->next;
    }
    return c;
}
void sort()
{

}
void reverse()
{

}
void sum()
{

}
void menu()
{
    printf("option\n");
    printf("=======\n");
    printf("1.insert at first\n");
    printf("2.insert at end\n");
    printf("3.insert at middle\n");
    printf("4.display\n");
    printf("5.delete\n");
    printf("6.count\n");
    printf("7.sort\n");
    printf("8.reverse\n");
    printf("9.sum\n");
    printf("10.exit\n");
    printf("enter your choice ");
}
int main()
{
    int i,num,ioc;
    while(1)
    {
        menu();
        scanf("%d",&i);
        switch(i)
        {
            case 1:
            printf("enter number ");
            scanf("%d",&num);
            insert_first(num);
            display();
            break;
            case 2:
            printf("enter number ");
            scanf("%d",&num);
            insert_last(num);
            display();
            break;
            case 3:
            printf("after which number do you want to insert\n");
            scanf("%d",&ioc);
            printf("enter the number to be inserted\n");
            scanf("%d",&num);
            insert_middle(num,ioc);
            display();
            break;
            case 4:
            display();
            break;
            case 5:
            printf("enter number to be deleted ");
            scanf("%d",&num);
            deleteitem(num);
            display();
            break;
            case 6:
            printf("element number is %d\n",count());
            break;
            case 7:
            sort();
            display();
            case 8:
            reverse();
            break;
            case 9:
            sum();
            break;
            case 10:
            return 0;
        }
    }
    return 0;
}