program to create a doubly circular linked list.

#include<stdio.h>

#include<conio.h>

struct circular

{

    int i;

    struct circular *front;

    struct circular *back;

};

int cnt=0;

struct circular *temp;

struct circular *head;

struct circular *p;

struct circular *mid;

struct circular *move;

void create(void);

void insert(void);

void display(void);

void del(void);

void main()

{

    int ch=0;

    while(ch!=5)

    {

        printf("\n1.CREATE");

        printf("\n2.INSERT");

        printf("\n3.DELETE");

        printf("\n4.DISPLAY");

        printf("\n5.EXIT");

        printf("\nEnter your choice=");

        scanf("%d",&ch);

if(ch==1)

        {

            create();

            cnt++;

            cnt++;

        }

if(ch==2)

        {

            insert();

            cnt++;

        }

if(ch==3)

        {

            del();

            cnt--;

        }

if(ch==4)

        {

            display();

        }

if(ch==5)

        {

            break;

        }

    }

    getch();

}

void create()

{

    head=(struct circular *)malloc(sizeof(struct circular));

    head->back=head;

    head->front=head;

printf("\nENTER THE DATA");

    scanf("%d",&head->i);

    temp=head;

temp->back=(struct circular *)malloc(sizeof(struct circular));

    temp=temp->back;

    temp->back=head;

    head->front=temp;

printf("\nENETER THE DATA");

    scanf("%d",&temp->i);

}

void insert()

{

    int add,t;

      printf("\n\t ENTER ANY NUMBER=");

    scanf("%d",&add);

    p=head;

    t=1;

    while(t<add)

    {

        p=p->back;

        t++;

    }

    mid=(struct circular *)malloc(sizeof(struct circular));

    printf("\n\n\nENTER THE DATA");

    scanf("%d",&mid->i);

      mid->back=p->back;

    p->back=mid;

    p->back->front=mid;

    mid->front=p;

}

void display()

{

    p=head;

    printf("\n%d-->",p->i);

    p=p->back;

    while(p!=head)

    {

        printf("\t%d-->",p->i);

        p=p->back;

    }

}

void del(void)

{

    int add,t;

      printf("\n\n\t ENTER ANY NUMBER");

    scanf("%d",&add);

    p=head;

    t=1;

    while(t<add-1)

    {

        p=p->back;

        t++;

    }

    mid=p->back;

    p->back=mid->back;

    mid->back->front=p;

    free(mid);

}