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


typedef struct row {
    int data[MAX];
    int f;
    int r;
} ROW;


int isFULL(ROW *);
int isEmpty(ROW *);
int add(ROW *, int);
int delete(ROW *, int *);
int print(ROW *buffer);


int main()
{
    ROW buffer;
    char choice;
    int data;

    buffer.f = buffer.r = -1;
    do
    {
        printf("[1] Add new\n");
        printf("[2] Delete\n");
        printf("[3] Print all\n");
        printf("[0] Exit\n");
        printf(">> ");

        fscanf(stdin, " %c", &choice);

        switch (choice)
        {
            case '1':
                printf("Enter number that you whis to add: ");

                fscanf(stdin, "%d", &data);

                if (!add(&buffer, data))
                {
                    printf("Couldn't add the number, the buffer is full.\n");
                }
                break;
            case '2':
                if (delete(&buffer, &data))
                {
                    printf("The number %d has been sucessfully deleted.\n", data);
                }
                else
                {
                    printf("Nothing to delete, the buffer is empty.\n");
                }

                break;
            case '3':
                if (!print(&buffer))
                {
                    printf("Nothing to print, the buffer is empty.\n");
                }
                break;
        }
        printf("\n");
    }  while (choice != '0');
    return 0;
}


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


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


int add(ROW *buffer, int data)
{
    if (isFULL(buffer))
    {
        return 0;
    }
    if (buffer->f == -1)
    {
        buffer->f = 0;
    }

    buffer->r = (buffer->r + 1) % MAX;
    buffer->data[buffer->r] = data;

    return 1;
}


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

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

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

    return 1;
}


int print(ROW *buffer)
{
    if (isEmpty(buffer))
    {
        return 0;
    }

    int i = buffer->f;

    if (buffer->f <= buffer->r)
    {
        while (i <= buffer->r)
        {
            printf("%d\n", buffer->data[i++]);
        }
    }
    else
    {
        while(i <= MAX - 1)
        {
            printf("%d\n", buffer->data[i++]);
        }
        i = 0;
        while(i <= buffer->r)
        {
            printf("%d\n", buffer[i++]);
        }
    }
    return 1;
}