CLL_MDP_DAN_d.c

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

struct cllist
{
    int data;
    struct cllist *next;
};

typedef struct cllist node;
node *head=NULL,*new1,*ptr;
int count=0;

void display_CLL()
{
    node *ptr;
    ptr=head;
    printf("\n");
    if(ptr==NULL)
    {
        printf("Empty List\n");
        return;
    }
    else
    {
        printf("Circular List Elements\n");
        do
        {
            printf("%d\t",ptr->data);
            ptr=ptr->next;
        }while(ptr!=head);
        getch();
    }
}

void CLL_dan()
{
    int n,i;
    node *loc,*locp,*last;
    printf("\nEnter position: ");
    scanf("%d",&n);
    if(n>count)
    {
        printf("Invalid Position\n");
        getch();
        return;
    }
    else
    {
        loc = head;
        for (i=2;i<=n;i++)
        {
            locp = loc;
            loc = loc->next;
        }
        if ((head == loc)&&(loc->next==head))
        {
            head = NULL;
            free(loc);
        }
        else if((head == loc) && (loc->next != head))
        {
            last=head;
            do
            {
                last=last->next;
            }while(last->next!=head);
            last->next=head->next;
            head = head->next;
            free(loc);
        }
        else if((head!=loc) && (loc->next == head))
        {
            locp->next =head;
            free(loc);
        }
        else
        {
            locp->next = loc->next;
            free(loc);
        }
    }
    count--;
}

void main()
{
    int ch;
    char op;
    head = (node*)malloc(sizeof(node));
    ptr=head;
    printf("Enter initial Linked List:\n");
    printf("Enter data: ");
    scanf("%d",&ptr->data);
    count++;
    do
    {
        printf("\nContinue Linked List? y or n: ");
        op=getch();
        switch(op)
        {
            case 'y':{
                new1=(node*)malloc(sizeof(node));
                ptr->next=new1;
                ptr=new1;
                printf("\nEnter data: ");
                scanf("%d",&ptr->data);
                count++;
                break;
            }
            case 'n': {
                ptr->next = head;
                break;
            }
            default: printf("\nPlease only input 'y' or 'n'\n");break;
        }
    }while (op!='n');
    system("cls");
    do
    {
        printf("\nLinked List Operations:\n");
        printf("1.\tDelete Nth Node\n2.\tDisplay Linked List\n3.\tExit");
        printf("\nChoice: ");
        scanf("%d",&ch);
        switch(ch)
        {
            case 1:CLL_dan();break;
            case 2:display_CLL();break;
            case 3:exit(1);
            default: {
                printf("\nInvalid Choice!\n");
                break;
            }
        }
    }while(ch!=3);
}