[НРС] Вежбе 9 (Припрема) - зад 1

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

#pragma pack(4)

char *napraviNiz(int);
void izracunaj(char *);
void ispisiNiz(char *);
node *izdvoj(char *);
void copyLEToBE(int, void *);
void ispisiListu(node *);

int main()
{
    int n;
    char *buffer;
    node *l;
    printf("Unesite ukupan broj izraza: ");
    scanf("%d", &n);
    buffer = napraviNiz(n);
    izracunaj(buffer);
    ispisiNiz(buffer);
    l = izdvoj(buffer);
    ispisiListu(l);
    free(l);
    free(buffer);
    return EXIT_SUCCESS;
}

char *napraviNiz(int n)
{
    char *buffer = (char *)malloc(sizeof(int) + n * sizeof(Izraz));
    int i;
    *buffer = n;
    for (i = sizeof(int); i < sizeof(int) + n * sizeof(Izraz); i += sizeof(Izraz))
    {
        int index = ((i - sizeof(int)) / sizeof(Izraz) * sizeof(Izraz));
        printf("Unesite broj 1 za %lld iteraciju: ", (i - sizeof(int)) / sizeof(Izraz));
        scanf("%hd", buffer + sizeof(int) + index);
        printf("Unesite operaciju za %lld iteraciju: ", (i - sizeof(int)) / sizeof(Izraz));
        fflush(stdin);
        scanf("%c", buffer + sizeof(int) + sizeof(short) + index);
        printf("Unesite broj 2 za %lld iteraciju: ", (i - sizeof(int)) / sizeof(Izraz));
        scanf("%hd", buffer + sizeof(int) + sizeof(short) + 2 * sizeof(char) + index);
    }
    return buffer;
}

void izracunaj(char *buffer)
{
    int n = *buffer,
        i;
    for (i = sizeof(int); i < sizeof(int) + n * sizeof(Izraz); i += sizeof(Izraz))
    {
        int index = ((i - sizeof(int)) / sizeof(Izraz)) * sizeof(Izraz);
        short br1 = *((short *)&buffer[sizeof(int) + index]),
              br2 = *((short *)&buffer[sizeof(int) + sizeof(short) + 2 * sizeof(char) + index]);
        char op = *(buffer + sizeof(int) + sizeof(short) + index);
        switch (op)
        {
        case '+':
            *((int *)&buffer[sizeof(int) + sizeof(short) + 2 * sizeof(char) + sizeof(short) + 2 * sizeof(char) + index]) = br1 + br2;
            break;
        case '-':
            *((int *)&buffer[sizeof(int) + sizeof(short) + 2 * sizeof(char) + sizeof(short) + 2 * sizeof(char) + index]) = br1 - br2;
            break;
        case '*':
            *((int *)&buffer[sizeof(int) + sizeof(short) + 2 * sizeof(char) + sizeof(short) + 2 * sizeof(char) + index]) = br1 * br2;
            break;
        case '/':
            *((int *)&buffer[sizeof(int) + sizeof(short) + 2 * sizeof(char) + sizeof(short) + 2 * sizeof(char) + index]) = br1 / br2;
            break;
        }
    }
}

void ispisiNiz(char *buffer)
{
    int n = *buffer,
        i;
    for (i = sizeof(int); i < sizeof(int) + n * sizeof(Izraz); i += sizeof(Izraz))
    {
        int index = ((i - sizeof(int)) / sizeof(Izraz)) * sizeof(Izraz);
        printf("--- Izraz broj: %lld ---\n", index / sizeof(Izraz));
        printf("%hd %c %hd = %d\n", *((short *)&buffer[sizeof(int) + index]),
               buffer[sizeof(int) + sizeof(short) + index],
               *((short *)&buffer[sizeof(int) + sizeof(short) + 2 * sizeof(char) + index]),
               *((int *)&buffer[sizeof(int) + sizeof(short) + 2 * sizeof(char) + sizeof(short) + 2 * sizeof(char) + index]));
    }
}

node *izdvoj(char *buffer)
{
    node *l;
    int n = *buffer,
        i;
    init(&l);
    for (i = sizeof(int); i < sizeof(int) + n * sizeof(Izraz); i += sizeof(Izraz))
    {

        int rez = *((int *)&buffer[i + sizeof(short) + 2 * sizeof(char) + sizeof(short) + 2 * sizeof(char)]);
        copyLEToBE(rez, &buffer[i + sizeof(short) + 2 * sizeof(char) + sizeof(short) + 2 * sizeof(char)]);
        addEnd(&l, *((Izraz *)&buffer[i]));
    }
    return l;
}

void copyLEToBE(int x, void *copy)
{
    int i;
    for (i = 0; i < sizeof(x); i++)
    {
        *((char *)copy + i) = *((char *)&x + sizeof(x) - 1 - i);
    }
}

void ispisiListu(node *l)
{
    node *t = l->next;
    int inx = 0;
    while (t != l)
    {
        printf("\n--- Ispis iteracije %d ---\n", inx++);
        printf("%hd %c %hd = %d", t->data.broj1,
               t->data.op,
               t->data.broj2,
               t->data.rezultat);
        t = t->next;
    }
}