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

#define ROZMIAR 5

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

struct fifo_pointers
{
    struct fifo_node *head, *tail;
}fifo;

void enqueue(struct fifo_pointers *fifo, int data)  ///dodawanie elementu do kolejki ( na koniec - ogon)
{
    struct fifo_node *new_node = (struct fifo_node *)malloc(sizeof(struct fifo_node));
    if(new_node)
    {
        new_node -> data = data;
        new_node -> next = NULL;
        if(fifo -> head == NULL)
            fifo->head=fifo->tail=new_node;
        else {
            fifo->tail->next = new_node ;
            fifo->tail = new_node;
        }
    }
    else
        printf("Nowy element nie zostal utworzony");

}

int dequeue(struct fifo_pointers *fifo)  ///usuwanie elementu z kolejki ( z poczatku - glowa)
{
    if(fifo->head)
    {
        struct fifo_node *tmp = fifo->head->next;
        int data = fifo->head->data;
        free(fifo->head);
        fifo->head = tmp;
        if(tmp == NULL)
            fifo->tail= NULL;
        return data;

    }
        return -1;
}

int show(struct fifo_pointers fifo)
{
    if(fifo.head)
    {
        printf(" %d ", fifo.head->data);
        fifo.head = fifo.head->next;
        show(fifo);
    }
    else
            return 0;
}

 int main ()
 {

    int i;
  for(i=1;i<=5;i++)
        enqueue(&fifo,i);

     printf(" Elementy w kolejka(rekurencja): \t");
        show( fifo);

    printf("\n Elementy usuniete: \t");
    while(fifo.head)
        printf(" %d ", dequeue(&fifo));
    puts(" ");
 return 0;
 }