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


// Structure that represents a singly-linked-list of integers
struct LinkedListItem {  
  int                     data;
  struct LinkedListItem  *next;
};

// Takes a list tail and adds the given item to it, returning the new item added
struct LinkedListItem *add(struct LinkedListItem *tail, int item) {
  struct LinkedListItem *newItem;
  newItem = (struct LinkedListItem *) malloc(sizeof(struct LinkedListItem));
  if (newItem == NULL) { 
    printf("Memory allocation error\n"); 
    exit(0); 
  }
  newItem->data = item;
  newItem->next = NULL;
  if (tail != NULL)
    tail->next = newItem;
  return newItem;
}

// Add all elements from items to the given Singly-Linked List and
// set the list to point to the head of the resulting list
void addAll(struct LinkedListItem **initTail, int items[], int size) {
  struct LinkedListItem *newItem;
  struct LinkedListItem *tail = *initTail;
  for (int i=0; i<size; i++) {
    newItem = (struct LinkedListItem *) malloc(sizeof(struct LinkedListItem));
    if (newItem == NULL) { 
      printf("Memory allocation error\n"); 
      exit(0); 
    }
    newItem->data = items[i];
    newItem->next = NULL;
    if (tail != NULL)
      tail->next = newItem;
    else
      *initTail = newItem; // newItem becomes the head of the list
    tail = newItem;
  }
}

// Print the contents of a Singly-Linked List
void printList(struct LinkedListItem *listItem) {
  while(listItem != NULL) {
    printf("%d", listItem->data);
    if (listItem->next != NULL)
      printf(" ---> ");
    else
      printf("\n");
    listItem = listItem->next;
  }
}

// Free all items in a Singly-Linked List 
void freeList(struct LinkedListItem *listItem) {
  struct LinkedListItem *nextItem;
  
  while(listItem != NULL) {
    nextItem = listItem->next;
    free(listItem);
    listItem = nextItem;
  }
}

int main() {
  struct LinkedListItem   *myList = NULL, *yourList = NULL;

  add(add(add(add(add(add(add(myList = add(NULL, 23),65),87),45),56),34),95),71);

  int  initData[] = {23, 65, 87, 45, 56, 34, 95, 71};
  addAll(&yourList, initData, sizeof(initData)/sizeof(int));

  printList(myList);
  printf("\n");
  printList(yourList);

  freeList(myList);
  freeList(yourList);
}