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

#define true 1
#define false 0

typedef unsigned short int bool;

struct list
{

    int *buffer;
    int head;
    int tail;
    int size;
};

bool createList(struct list *ptr, int size)
{
    ptr->size = size;
    ptr->buffer = malloc(ptr->size * sizeof(int));

    if (ptr->buffer == NULL)
    {
        return false;
    }
    ptr->head = 0;
    ptr->tail = 0;

    return true;
}

bool addElement(struct list *ptr, int value)
{
    if (ptr->tail + 1 % ptr->size != ptr->head)
    {
        ptr->buffer[ptr->tail] = value;
        ptr->tail = ++ptr->tail % ptr->size;
        return true;
    }
    // Lista piena
    return false;
}

bool addElementFirst(struct list *ptr, int value)
{
    if (ptr->tail + 1 % ptr->size != ptr->head)
    {
        int prec = (ptr->head - 1 + ptr->size) % ptr->size;
        ptr->buffer[prec] = value;
        ptr->head = prec;
        return true;
    }
    //lista piena
    return false;
}

bool printLista(struct list *ptr)
{
    if (ptr->head == ptr->tail)
    {
        printf("Lista vuota \n");
        return false;
    }

    int val = ptr->head;

    while (val != ptr->tail) {
        printf("%d \t", ptr->buffer[val]);
        val = ++val % ptr->size;
    }

    printf("\n");

    return true;
}

int ord_insert2(struct list * ptr, int val) {
    if (ptr->head != (++ptr->tail)%ptr->size) {
        int pos = ptr->tail, prec = (pos - 1 + ptr->size) % ptr->size;
        while (!(ptr->buffer[prec] < val || pos == ptr->head)) {
            ptr->buffer[pos] = ptr->buffer[prec];
            pos = prec;
        }
        ptr->buffer[pos] = val;
        return true;
    }
    return false;
}

bool ins_ord(struct list *ptr, int value) {

    if (1+ptr->tail % ptr->size == ptr->head) {
        return false;
    }

    int val = ptr->tail;
    ptr->tail = ++ptr->tail % ptr->size;
    while (value < ptr->buffer[(val-1 + ptr->size) % ptr->size] && (val-1 + ptr->size) % ptr->size != ptr->head) {
        ptr->buffer[val] = ptr->buffer[(val-1 + ptr->size) % ptr->size];
        val = (val-1 + ptr->size) % ptr->size;
    }
    ptr->buffer[val] = value;

}

bool ord_insert3(struct list * ptr, int val) {

    //if (ptr->tail+1%ptr->size == ptr->head) return false;

    int pos = ptr->tail;
    ptr->tail = ptr->tail +1 % ptr->size;

    if (ptr->buffer[(pos-1+ptr->size) % ptr->size] > val) {
        ptr->buffer[pos] = val;
        return true;
    }

    do {
        int prec = (pos-1+ptr->size) % ptr->size;
        ptr->buffer[pos] = ptr->buffer[prec];

        if (ptr->buffer[prec] > val || prec == ptr->head) {
            ptr->buffer[pos] = val;
            return true;
        }

        pos = prec;

    } while (pos != ptr->head);

    return false;
}

int main()
{
    struct list lista;

    createList(&lista, 30);

    printLista(&lista);

    addElement(&lista, 2);
    addElement(&lista, 4);
    addElement(&lista, 6);
    addElement(&lista, 8);
    addElementFirst(&lista, -1);


    printLista(&lista);

    ord_insert3(&lista, -2);
    printLista(&lista);

}