#include <stdio.h>
#include <stdlib.h>
#define MAX_POLINOM_SIZE (1024)

typedef struct _cvor* Position;
typedef struct _cvor
{
    int eksponent;
    int koeficijent;
    Position next;
}cvor;

int ProcitajDatoteke(char* imeDatoteke, Position pp, Position dp);
int UcitajPolinomIzStringa(char* ulazniString, Position trenutniCvor);
int DodajUListuSortirano(Position trenutniCvor, int koeficijent, int eksponent);
int KreirajCvorIDodajIzaTrenutnog(Position trenutniCvor, int koeficijent, int eksponent);
int DodajIzaTrenutnog(Position noviCvor, Position trenutniCvor);
void IspisiPolinom(char* opis, Position trenutniCvor);
int ZbrojiPolinome(Position pp, Position dp, Position sumaPolinoma);
int PomnoziPolinome(Position pp, Position dp, Position umnozakPolinoma);
void DealocirajMemoriju(Position trenutniCvor);

int main(int argc, char* argv[])
{
    cvor pp, dp;
    cvor sumaPolinoma, umnozakPolinoma;
    pp.next = NULL;
    dp.next = NULL;
    sumaPolinoma.next = NULL;
    umnozakPolinoma.next = NULL;
    ProcitajDatoteke("polinomi.txt", &pp, &dp);
    IspisiPolinom("\nPrvi polinom", pp.next);
    IspisiPolinom("Drugi polinom", dp.next);
    ZbrojiPolinome(&pp, &dp, &sumaPolinoma);
    IspisiPolinom("Zbroj polinoma", sumaPolinoma.next);
    PomnoziPolinome(&pp, &dp, &umnozakPolinoma);
    IspisiPolinom("Umnozak polinoma", umnozakPolinoma.next);

    DealocirajMemoriju(&pp);
    DealocirajMemoriju(&dp);
    DealocirajMemoriju(&sumaPolinoma);
    DealocirajMemoriju(&umnozakPolinoma);
    return 0;

}
int ProcitajDatoteke(char* imeDatoteke, Position prviPolinom, Position drugiPolinom)
{
    FILE* f;
    char buffer[MAX_POLINOM_SIZE];
    f = fopen(imeDatoteke, "r");

    fgets(buffer, MAX_POLINOM_SIZE, f);
    UcitajPolinomIzStringa(buffer, prviPolinom);

    fgets(buffer, MAX_POLINOM_SIZE, f);
    UcitajPolinomIzStringa(buffer, drugiPolinom);

    return 0;

}
int UcitajPolinomIzStringa(char* string, Position position)
{
    int koef, pot, offset;
    while (sscanf(string, " %d %d %n", &koef, &pot, &offset) != EOF)
    {
        DodajUListuSortirano(position, koef, pot);
        string += offset;
    }
    return 0;

}
int DodajUListuSortirano(Position position, int koeficijent, int eksponent)
{
    while (position->next != NULL && position->next->eksponent > eksponent)
        position = position->next;

    if (position->next != NULL && position->next->eksponent == eksponent)
        position->next->koeficijent += koeficijent;
    else
        KreirajCvorIDodajIzaTrenutnog(position, koeficijent, eksponent);
    return 0;

}
int KreirajCvorIDodajIzaTrenutnog(Position currentPosition, int koeficijent, int eksponent)
{
    Position q;
    q = (Position)malloc(sizeof(cvor));
    q->eksponent = eksponent;
    q->koeficijent = koeficijent;
    DodajIzaTrenutnog(q, currentPosition);
    return 0;

}
int DodajIzaTrenutnog(Position noviCvor, Position currentPosition)
{
    noviCvor->next = currentPosition->next;
    currentPosition->next = noviCvor;

    return 0;
}
void IspisiPolinom(char* title, Position currentPosition)
{
    bool first = true;
    printf("%s=", title);
    while (currentPosition != NULL)
    {
        if (first == true)
        {
            if (currentPosition->koeficijent == 1 && currentPosition->eksponent == 0)
                printf("1");
            if (currentPosition->koeficijent == -1 && currentPosition->eksponent == 0)
                printf("- 1");
            if (currentPosition->koeficijent == 1 && currentPosition->eksponent > 0)
                printf("x^%d", currentPosition->eksponent);
            if (currentPosition->koeficijent == 1 && currentPosition->eksponent < 0)
                printf("x^(%d)", currentPosition->eksponent);
            if (currentPosition->koeficijent > 0 && currentPosition->koeficijent != 1 && currentPosition->eksponent > 0)
                printf("%dx^%d", currentPosition->koeficijent, currentPosition->eksponent);
            if (currentPosition->koeficijent < 0 && currentPosition->koeficijent != -1 && currentPosition->eksponent > 0)
                printf("-%dx^%d", (-1) * currentPosition->koeficijent, currentPosition->eksponent);
            if (currentPosition->koeficijent > 0 && currentPosition->koeficijent != 1 && currentPosition->eksponent < 0)
                printf("%dx^(%d)", currentPosition->koeficijent, currentPosition->eksponent);
            if (currentPosition->koeficijent < 0 && currentPosition->koeficijent != -1 && currentPosition->eksponent < 0)
                printf("-%dx^(%d)", (-1) * currentPosition->koeficijent, currentPosition->eksponent);
            first = false;
        }
        else
        {
            if (currentPosition->koeficijent == 1 && currentPosition->eksponent == 0)
                printf(" + 1");
            if (currentPosition->koeficijent == -1 && currentPosition->eksponent == 0)
                printf(" - 1");
            if (currentPosition->koeficijent == 1 && currentPosition->eksponent > 0)
                printf(" + x^%d", currentPosition->eksponent);
            if (currentPosition->koeficijent == 1 && currentPosition->eksponent < 0)
                printf(" + x^(%d)", currentPosition->eksponent);
            if (currentPosition->koeficijent > 0 && currentPosition->eksponent > 0)
                printf(" + %dx^%d", currentPosition->koeficijent, currentPosition->eksponent);
            if (currentPosition->koeficijent < 0 && currentPosition->eksponent > 0)
                printf(" - %dx^%d", (-1) * currentPosition->koeficijent, currentPosition->eksponent);
            if (currentPosition->koeficijent > 0 && currentPosition->eksponent < 0)
                printf(" + %dx^(%d)", currentPosition->koeficijent, currentPosition->eksponent);
            if (currentPosition->koeficijent < 0 && currentPosition->eksponent < 0)
                printf(" - %dx^(%d)", (-1) * currentPosition->koeficijent, currentPosition->eksponent);
        }
        currentPosition = currentPosition->next;
    }
    printf("\r\n");
}
int ZbrojiPolinome(Position pp, Position dp, Position sumaPolinoma)
{
    Position temp;
    pp = pp->next;
    dp = dp->next;
    while (pp != NULL && dp != NULL)
    {
        if (pp->eksponent > dp->eksponent)
        {
            DodajUListuSortirano(sumaPolinoma, pp->koeficijent, pp->eksponent);
            pp = pp->next;
        }
        else if (pp->eksponent < dp->eksponent)
        {
            DodajUListuSortirano(sumaPolinoma, dp->koeficijent, dp->eksponent);
            dp = dp->next;
        }
        else
        {
            DodajUListuSortirano(sumaPolinoma, pp->koeficijent + dp->koeficijent, dp->eksponent);
            pp = pp->next;
            dp = dp->next;
        }
    }
    if (pp == NULL) temp = dp;
    else temp = pp;
    while (temp != NULL)
    {
        DodajUListuSortirano(sumaPolinoma, temp->koeficijent, temp->eksponent);
        temp = temp->next;
    }
    return 0;

}
int PomnoziPolinome(Position pp, Position dp, Position umnozakPolinoma)
{
    Position pocetakD = dp->next;
    pp = pp->next;
    dp = dp->next;
    while (pp != NULL)
    {
        while (dp != NULL)
        {
            DodajUListuSortirano(umnozakPolinoma, pp->koeficijent * dp->koeficijent, pp->eksponent + dp->eksponent);
            dp = dp->next;
        }
        pp = pp->next;
        dp = pocetakD;
    }

    return 0;
}
void DealocirajMemoriju(Position trenutniCvor)
{

}