#include <stdio.h>
#include <stdlib.h>
#define MAX 5

typedef struct BUFFER {
    int array[MAX];
    int f, r;
} BUFFER;

typedef struct node {
    int num;
    struct node *next;
} NODE;

int isFull(BUFFER *buffer);
int isEmpty(BUFFER *buffer);

int addToBuffer(BUFFER *buffer, int data);
void options(BUFFER *buffer, NODE **tos);
int delete(BUFFER *buffer, int *data);
int writeFromBuffer(BUFFER *buffer);

void addToStack(NODE **tos, int *num);
int pop(NODE **tos, int *num);
void writeFromStack(NODE **tos);

int main() {
    BUFFER buffer; buffer.f = buffer.r = -1; char c; int num;
    NODE *tos;

    options(&buffer, &tos);

    writeFromStack(&tos);
    writeFromBuffer(&buffer);
    return 0;
}

void options(BUFFER *buffer, NODE **tos){
    int o, pom;
    printf("Izaberi operaciju: \nDodavanje novog elementa u bafer [1] \nUklanjanje elementa iz bafera    [2] \nIspis svih elemenata iz bafera   [0]\n");
    scanf("%d", &o);

    if(o == 1){

        int n;
        printf("Unesite prirodan num\n");
        scanf("%d", &n);

        if(addToBuffer(buffer, n) == 0)
            printf("Bafer je pun.\n");
        else
            addToStack(tos, &n);

        options(buffer, tos);

    } else if (o == 2) {

        int n;
        delete(buffer, &n);
        options(buffer, tos);

    }else if (o == 0) {
        return;
    }else
        printf("Unesena opcija ne postoji.");

}


//stack
void addToStack(NODE **tos, int *num) {
  NODE *new = (NODE *)malloc(sizeof(NODE));
  new->num = *num;
  new->next = *tos;
  *tos = new;
}

int pop(NODE **tos, int *num) {
  if (*tos == 0) return 0;
  NODE *p = *tos;
  *num = p->num;
  *tos = p->next;
  free(p);
  return 1;
}

void writeFromStack(NODE **tos) {
  int num; int rb = 1;

  while (pop(tos, &num))
    printf("%d. broj: %d\n", rb++, num);

}

//buffer
int addToBuffer(BUFFER *buffer, int data){
  if (isFull(buffer))
    return 0;
  if (buffer->f == -1)
    buffer->f = 0;
  buffer->r = (buffer->r + 1) % MAX;
  buffer->array[buffer->r] = data;
  return 1;
}

int delete(BUFFER *buffer, int *data){
  if (isEmpty(buffer))
    return 0;

  *data = buffer->array[buffer->f];

  if (buffer->f == buffer->r)
    buffer->f = buffer->r = -1;
  else
    buffer->f = (buffer->f + 1) % MAX;

  return 1;
}

int writeFromBuffer(BUFFER *buffer) {
  if (isEmpty(buffer))
    return 0;

  int i = buffer->f;

  if (buffer->f <= buffer->r){

    while (i <= buffer->r)
      printf("%d ", buffer->array[i++]);

  } else {

    while (i <= MAX - 1)
      printf("%d ", buffer->array[i++]);

    i = 0;
    while (i <= buffer->r)
      printf("%d ", buffer->array[i++]);

  }

  return 1;
}

int isFull(BUFFER *buffer) {
    return (buffer->r + 1) % MAX == buffer->f;
}

int isEmpty(BUFFER *buffer) {
    return buffer->f == -1;
}