Write a C program to remove duplicates from a sorted linked list.

#include
#include "linkedlist.h"

#define LL_LIMIT 6
#define LL_DUP1 4

NODE* createLL()
{
        int index=LL_LIMIT;
        NODE* headNode = NULL;
        while(index > 0)
        {
                headNode = addAtHead(headNode, index);
                if (index == LL_DUP1)
                {
                        headNode = addAtHead(headNode, index);
                }
                index--;
        }
        return headNode;
}

int removeDupNode(NODE* headNode)
{
        NODE* dupNode;
        if (headNode == NULL)
        {
                printf("List is Empty\n");
                return 1;
        }

        while(headNode->next != NULL)
        {
                if(headNode->data == headNode->next->data)
                {
                        printf("Duplicate data is %d\n", headNode->next->data);
                        dupNode = headNode->next;
                        headNode->next = dupNode->next;
                        free(dupNode);
                }
                headNode = headNode->next;
        }
        return 0;
}

int main()
{
        NODE* headNode = NULL;

        headNode = createLL();

        displayAll(headNode);

        if(!removeDupNode(headNode))
        {
                displayAll(headNode);
        }
}