Doubly-Linked Lists Learning

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

typedef struct listitem
{
    struct listitem *next;
    struct listitem *prev;
    int data;
} LISTITEM;

int main()
{
    LISTITEM *temp, head;

    head.next = (LISTITEM*)&head;   // contains the address of head
    head.prev = (LISTITEM*)&head;   // also contains the address of head
    head.data = -1;

    // populate the list
    for(int i = 0; i < 3; i++)
    {
        temp = malloc(sizeof(LISTITEM));
        temp->data = i;
        temp->next = head.next;
        head.next = temp;
        temp->prev = &head;
        temp->next->prev = temp;
    }

    // now lets see what we have going forward
    temp = head.next;
    while(temp != &head)
    {
        printf("forward list item: current is %p; next is %p; prev is %p; data is %d\n", temp, temp->next, temp->prev, temp->data);
        temp = temp->next;
    }

    // and going backwards
    temp = head.prev;
    while(temp != &head)
    {
        printf("forward list item: current is %p; next is %p; prev is %p; data is %d\n", temp, temp->next, temp->prev, temp->data);
        temp = temp->prev;
    }
    return 0;
}