/*4. Napisati program za zbrajanje i množenje polinoma.
Koeficijenti i eksponenti se čitaju iz datoteke.
Napomena: Eksponenti u datoteci nisu nužno sortirani. */

#define _CRT_SECURE_NO_WARNINGS
#define MAX_FILENAME 50


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


//Struct poli

struct node;
typedef struct node* Pnode;
struct node
{
        int koef;
        int exp;
        Pnode Next;
};

//Functions



//Main
int main()
{
    struct node P1, P2, P3, P4;
    P1.Next = NULL;
    P2.Next = NULL;
    P3.Next = NULL;
    P4.Next = NULL;

    FILE *fp = NULL;
    Pnode q, temp,temp1,temp2;
    char ime_dat[MAX_FILENAME];
    //Prva
    printf("Upisi ime prve datoteke:\n");
    scanf(" %s", ime_dat);
    fp = fopen(ime_dat, "r");
    if (NULL == fp)
        printf("Greska tokom otvaranja datoteke");
    while (!feof(fp))
    {
        q = (Pnode)malloc(sizeof(struct node));
        fscanf(fp, " %d %d", &q->koef, &q->exp);
        temp = &P1;
        while (temp->Next != NULL && temp->Next->exp > q->exp)
            temp = temp->Next;

        if (temp->Next != NULL && temp->Next->exp == q->exp)
        {
            temp->Next->koef =temp->Next->koef + q->koef;
            free(q);
            if (temp->Next->koef == 0)
            {
                q = temp->Next;
                temp->Next = q->Next;

                free(q);
            }
        }
        else
        {
            q->Next = temp->Next;
            temp->Next = q;
        }
    }
    fclose(fp);
    //Druga
    printf("Upisi ime druge datoteke:\n");
    scanf(" %s", ime_dat);
    fp = fopen(ime_dat, "r");
    if (NULL == fp)
        printf("Greska tokom otvaranja datoteke");
    while (!feof(fp))
    {
        q = (Pnode)malloc(sizeof(struct node));
        fscanf(fp, " %d %d", &q->koef, &q->exp);
        temp = &P2;
        while (temp->Next != NULL && temp->Next->exp > q->exp)
            temp = temp->Next;

        if (temp->Next != NULL && temp->Next->exp == q->exp)
        {
            temp->Next->koef = temp->Next->koef + q->koef;
            free(q);
            if (temp->Next->koef == 0)
            {
                q = temp->Next;
                temp->Next = q->Next;

                free(q);
            }
        }
        else
        {
            q->Next = temp->Next;
            temp->Next = q;
        }
    }
    fclose(fp);

    //Ispis prve
    printf("Ispis prvog polinoma:\n");
    temp = P1.Next;
    while (temp != NULL)
    {
        if (temp->koef > 0)
            printf(" +%dx^%d", temp->koef, temp->exp);
        else
            printf(" %dx^%d", temp->koef, temp->exp);
        temp = temp->Next;
    }
    //Ispis druge
    printf("\nIspis drugog polinoma:\n");
    temp = P2.Next;
    while (temp != NULL)
    {
        if (temp->koef > 0)
            printf(" +%dx^%d", temp->koef, temp->exp);
        else
            printf(" %dx^%d", temp->koef, temp->exp);
        temp = temp->Next;
    }

    printf("\nZbrajanje polioma:\n");
    //Zbrajanje polinoma
    temp = P1.Next;
    temp1 = P2.Next;
    temp2 = P3.Next;
    while (temp != NULL && temp1 != NULL)
    {
        q = (Pnode)malloc(sizeof(struct node));


        if (temp->exp > temp1->exp)
        {
            q->exp = temp->exp;
            q->koef = temp->koef;
            temp = temp->Next;
        }
        else if (temp->exp < temp1->exp)
        {
            q->exp = temp1->exp;
            q->koef = temp1->koef;
            temp1 = temp1->Next;
        }
        else
        {
            q->exp = temp->exp;
            q->koef = temp->koef + temp1->koef;
            temp = temp->Next;
            temp1 = temp1->Next;
        }

        q->Next = temp2->Next;
        temp2->Next = q;

        temp2 = q;
    }
    //Ispis sume
    printf("\nIspis sume:\n");

    temp = P3.Next;
    while (temp != NULL)
    {
        if (temp->koef > 0)
            printf(" +%dx^%d", temp->koef, temp->exp);
        else
            printf(" %dx^%d", temp->koef, temp->exp);
        temp = temp->Next;
    }


    getchar();
    getchar();
    return 0;

}