DOUBLE LINKED LIST (ASSIGNMENT)

#include<stdio.h>
#include<stdlib.h>

typedef struct node
{

    int a;
    char ch;
    struct node*next;
    struct node*previous;
} node;
node*head;




void display()
{

    node *list=head;
    while(list !=NULL)
    {
        printf("A: %d\n",list->a);
        printf("C: %c\n",list->ch);
        printf("\n");

        list=list->next;

    }
}



void insert_at_first(int aN, char chN)
{
    node *N=(node*)malloc(sizeof(node));
    N->a=aN;
    N->ch=chN;
    N->next=NULL;
    N->previous=NULL;
    if(head==NULL)
    {
        head=N;
        return;
    }
    N->next=head;
    head->previous=N;
    head=N;
}




void insert_at_end(int aN,char chN)
{

    node*N=(node*)malloc(sizeof(node));
    N->a=aN;
    N->ch=chN;
    N->next=NULL;
    N->previous=NULL;
    node*list=head;
    if(head==NULL)
    {
        head=N;
    }
    else
    {
        while(list->next!=NULL)
        {
            list=list->next;
            N->previous=list;
        }
        list->next=N;
        N->next=NULL;
        N->previous=list;


    }

}




void insert_nth(int n,int aN,char chN)
{
    node *N=(node*)malloc(sizeof(node));
    N->a=aN;
    N->ch=chN;
    N->next=NULL;
    N->previous=NULL;
    if(n==1)
    {
        N->previous=NULL;
        N->next=head;
        head=N;

        return;
    }
    else
    {
        node*list=head;
        n=n-2;
        while(n!=0&&list->next!=NULL)
        {
            list=list->next;
            n--;
        }
        N->next=list->next;
        if(list->next !=NULL)
        {
            list->next->previous=N;
        }

        list->next=N;
    }
}






int search(int n)
{
    node*list=head;
    int x=0;
    while(list!=NULL)
    {
        if(list->a==n)
        {
            printf("\n%d is Found\n\n",n);
            x=1;
            break;
        }
        else

            list=list->next;
    }
    if(x==0)
    {
        printf("\n%d is  Not Found\n\n",n);
    }
}



void create()
{
    int value;
    char ch;
    while(1)
    {
        printf("   \nENTER  NUMBER & Character(-0 for exit)\n");
        scanf("%d",&value);
        if(value==-0)
        {
            break;
        }
        scanf(" %c",&ch);


        insert_at_end(value,ch);

    }


}



void delete_pos(int pos)
{
    node *list=head,*temp=NULL,*tail;


    if(pos==1)
    {
        if(list->next==NULL)
        {
            printf("DATA DELETED\n\n");
            free(list);
        }
        else
        {
            head=list->next;
            head->previous=NULL;
            printf("DATA DELETED\n\n");
            free(list);
        }
    }
    else
    {
        pos=pos-2;
        while(pos!=0 && list->next!=NULL)
        {
            list=list->next;
            pos--;
            if(list==NULL)
            {
                printf("NO DATA FOUND!!\n\n");
                break;
            }
        }
        if(list->next==NULL)
        {
            printf("You Choose Wrong Position!!\n\n");
        }
        else if(list==NULL && pos==0)
        {
            temp=tail;
            tail=temp->previous;
            tail->next=NULL;
            printf("DATA DELETED\n\n");
            free(temp);
        }
        else if(list!=NULL && pos==0)
        {
            temp=list->next;
            temp->next->previous=list;
            list->next=temp->next;
            printf("DATA DELETED\n\n");
            free(temp);
        }
    }
}



void delete_item(int value)
{
    node *list = head, *temp=NULL;
    int x = 0;

    while(list!=NULL)
    {
        if(list->a==value)
        {
            if(temp==NULL)
            {
                head = list->next;
                head->previous=NULL;
            }
            else
                temp->next = list->next;


            printf("%d is deleted from list\n", value);
            x = 1;
            free(list);
            break;
        }
        temp = list;
        list = list->next;
        list->previous=temp;
    }
    if(x==0)
        printf("Key not found!\n");
}



void MENU()
{
    int x,af,l;
    char cf;

    printf("   \n Create Doubly Linked List \n");
    create();
    display();

    printf("   \n Insert At FIRST \n");
    scanf("%d",&af);
    scanf(" %c",&cf);

    insert_at_first(af,cf);
    display();
    printf("   \n Insert At END \n");
    scanf("%d",&af);
    scanf(" %c",&cf);

    insert_at_end(af,cf);
    display();

    printf("   \n Insert At Nth(pos,int,char) \n");
    scanf("%d",&x);
    scanf("%d",&af);
    scanf(" %c",&cf);
    insert_nth(x,af,cf);
    display();

    printf("   \n SEARCH VALUE \n");
    scanf("%d",&l);
    search(l);

    printf("   \n DELETE BY POSITION \n");
    scanf("%d",&x);
    delete_pos(x);
    display();

    printf("   \n DELETE BY VALUE \n");
    scanf("%d",&l);
    delete_item(l);

    printf("   \n FINAL VALUE \n");
    display();
    return 0;

}




int main()
{
    head=NULL;
    MENU();

}