#ifndef BASIC_H
#define BASIC_H

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

struct Node{
  char * words;
  int count;
  struct Node *nextPtr;
};

struct Node *makeNode(char *words, int size)
{
  struct Node *newNodePtr=(struct Node *)malloc(sizeof(struct Node));

  if (newNodePtr==NULL)
    {
      printf("Out of memory!\n");
      exit(0);
    }

  else 
    {
      newNodePtr->words=(char *)malloc(sizeof(char)*size);
      strcpy(newNodePtr->words,words);
      newNodePtr->count=0; /* initialize the counter */
  }
  return newNodePtr;
}

struct List
{
  int count;
  struct Node *headPtr;
};

void initializeList(struct List *listPtr)
{
 listPtr->headPtr=NULL;
 listPtr->count=0;
}

struct Node * setPosition(struct List *listPtr,int position)
{
  int i;
  struct Node *nodePtr=listPtr->headPtr;

  if(position<0||position>=listPtr->count)
    {
      printf("Invalid position\n");
      exit(0);
    }

else
  {
    for (i=0;i<position;i++)
      {
	nodePtr=nodePtr->nextPtr;
      }
  }
  return nodePtr;
}

void insertItem(struct List *listPtr,char *words,int size,int position)
{
  struct Node *newNodePtr=makeNode(words,size);
  struct Node * nodePtr=NULL;
 
  if (position==0)
    {
      newNodePtr->nextPtr=listPtr->headPtr;
      listPtr->headPtr=newNodePtr;
    }
else
  {
    nodePtr=setPosition(listPtr,position-1);
    newNodePtr->nextPtr=nodePtr->nextPtr;
    nodePtr->nextPtr=newNodePtr;
  }
 
  listPtr->count++;
}

int listEmpty(struct List *listPtr)
{
  if((listPtr->count)==0)
	    return 1;
 else return 0;
}

void deleteNode(struct List *listPtr, int position)
{
  struct Node * oldNodePtr=NULL;
  struct Node * nodePtr=NULL;

  if (!listEmpty(listPtr) && position<listPtr->count)
    {
      if (position==0)
	{
	  oldNodePtr=listPtr->headPtr;
	  listPtr->headPtr=oldNodePtr->nextPtr;
	}
else
  {
    nodePtr=setPosition(listPtr,position-1);
    oldNodePtr=nodePtr->nextPtr;
    nodePtr->nextPtr=oldNodePtr->nextPtr;
  }
      listPtr->count--;
      free(oldNodePtr);
    }
else

  {
    printf("List is empty or invalid position\n");
    exit(0);
 }
}

#define ON 1
#define OFF 0

#endif