vezaneListe mk2

#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#define STRING_MAX_LENGTH (50)

typedef struct _osoba* Position;

typedef struct _osoba
{
    char ime[STRING_MAX_LENGTH];
    char prezime[STRING_MAX_LENGTH];
    int godinaRodenja;
    Position next;
}Student;

typedef struct _studentPodaci
{
    char ime[STRING_MAX_LENGTH];
    char prezime[STRING_MAX_LENGTH];
    int godinaRodenja;
}StudentPodaci;

int InsertAfter(Position head, StudentPodaci studentPodaci);
int InsertEnd(Position position, StudentPodaci studentPodaci);
void IspisListe(Position head);
int DeleteElement(Position position);
Position FindPreviousElement(Position head, char *prezime);

int IspisIzbornika();
void PrintElement(Position position);
StudentPodaci GetStudentDataFromConsole();
void FreeAlocatedData(Position head);

int InsertBefore(Position position, StudentPodaci studentPodaci);
int SwapElements(Position prev, Position first);
int WriteIntoFile(Position head, char name);
int SortList(Position head);
int ElementCounter(Position head);

int main(int agrc, char *argv[])
{
    char izbor = 0;
    char prezime[STRING_MAX_LENGTH];
    char fileName[STRING_MAX_LENGTH] = "lista.txt";
    Student head;
    StudentPodaci bufferStudent;
    Position bufferPosition;

    head.next = NULL;

    while (izbor != 'K' && izbor != 'k')
    {
        IspisIzbornika();
        scanf(" %c", &izbor);
        switch (izbor)
        {
        case '1':
            bufferStudent = GetStudentDataFromConsole();
            InsertAfter(&head, bufferStudent);
            break;
        case '2':
            IspisListe(&head);
            break;
        case '3':
            bufferStudent = GetStudentDataFromConsole();
            InsertEnd(&head, bufferStudent);
            break;
        case '4':
            printf("\nUnesi prezime studenta cije podatke ispisujemo: ");
            scanf("%s", prezime);
            bufferPosition = FindPreviousElement(&head, prezime);
            if (bufferPosition != NULL)
                PrintElement(bufferPosition->next);
            else
                printf("\nElement ne postoji u listi.");
            break;
        case '5':
            break;
        case '6':
            WriteIntoFile(&head, fileName);
            break;
        case 'k':
        case 'K':
            break;
        default:
            printf("\r\nPogresan izbor <%c>.\r\nPokusajte ponovno.\r\n", izbor);
            break;
        }
    }

    FreeAlocatedData(&head);
    IspisListe(&head);
}

int IspisIzbornika()
{
    printf("\r\n\r\n");
    printf("\t1. Unos elementa u listu\r\n");
    printf("\t2. Ispis liste\r\n");
    printf("\t3. Unos na kraj\r\n");
    printf("\t4. Pronadji po prezimenu\r\n");
    printf("\t5. Izbrisi po prezimenu\r\n");
    printf("\t6. Upisi u datoteku\r\n");
    printf("\tK. Izlaz iz programa\r\n");
    printf("\r\n\tIzbor : ");

    return 0;
}

int InsertAfter(Position position, StudentPodaci studentPodaci)
{
    Position newItem = NULL;
    if (position == NULL)
        return -1;

    newItem = (Position)malloc(sizeof(Student));

    if (newItem == NULL)
        return -2;

    //inicijalizacija alocirane strukture
    newItem->next = NULL;
    newItem->godinaRodenja = studentPodaci.godinaRodenja;
    strcpy(newItem->ime, studentPodaci.ime);
    strcpy(newItem->prezime, studentPodaci.prezime);
    //unos u listu
    newItem->next = position->next;
    position->next = newItem;

    return 0;
}

int InsertEnd(Position position, StudentPodaci studentPodaci)
{
    while (position->next != NULL)
        position = position->next;

    InsertAfter(position, studentPodaci);

    return 0;
}

void IspisListe(Position head)
{
    while (head->next != NULL)
    {
        printf("%s %s %d", head->next->ime, head->next->prezime, head->next->godinaRodenja);
        printf("\n");
        head = head->next;
    }
}

int DeleteElement(Position position)
{
    Position temp = NULL;
    if ((position->next != NULL || position->next->next != NULL) && position->next->next->ime != NULL)
    {
        temp = position->next;
        free(position->next);
        position = temp;
        return 1;
    }
    else
        return -1;
}

Position FindPreviousElement(Position head, char *prezime)
{
    Position temp = NULL;
    if ((head->next != NULL || head->next->next != NULL) && head->next->next->prezime != NULL)
        temp = head->next;

    return temp;
}

void PrintElement(Position position)
{
    if (position->next != NULL)
        printf("%s %s %d /n", position->ime, position->prezime, position->godinaRodenja);
}

StudentPodaci GetStudentDataFromConsole()
{
    StudentPodaci tempStudent;

    printf("Unesi ime, prezime i godinu rodenja: \n");
    scanf(" %s %s %d", tempStudent.ime, tempStudent.prezime, &tempStudent.godinaRodenja);
    printf("\n");

    return tempStudent;
}

void FreeAlocatedData(Position head)
{
    Position temp = NULL;
    temp = head;
    while (temp->next != NULL)
    {
        free(temp->ime);
        free(temp->prezime);
        free(temp->godinaRodenja);
    }
    free(head);
}

int SwapElements(Position prev, Position first)
{
    Position temp = first->next;

    prev->next = first->next;

    if (temp == NULL)
    {
        return -1;
    }

    first->next = temp->next;
    temp->next = first;
    return 0;
}

int WriteIntoFile(Position head, char name)
{
    FILE *f;
    f = fopen(name, "w");

    if (f == NULL)
    {
        return -1;
    }
    else
    {
        head = head->next;
        while (head != NULL)
        {
            fprintf(f, "%s %s %d \n", head->ime, head->prezime, head->godinaRodenja);
            head = head->next;
        }
        fclose(f);
        return 0;
    }
}

int ElementCounter(Position head)
{
    int counter = 0;
    head->next;
    while (head->next != NULL)
    {
        counter++;
    }

    return counter;
}

int InsertBefore(Position position, StudentPodaci studentPodaci)
{
    Position temp = NULL;
    if ((position->next != NULL || position->next->next != NULL))
        temp = position->next;

    InsertAfter(temp, studentPodaci);

    return 0;
}

int SortList(Position head)
{
    int i = 0;
    int j = 0;
    int n = ElementCounter(head);

    for (i = 0; i < j - 1; i++)
        for (j = 0; j < i - n - 1; j++)
            SwapElements(head, head->next);

    return 0;
}

int ReadFromFile(Position head, char fileName)
{
    FILE *f;
    f = fopen(fileName, "r");
    StudentPodaci temp;

    if (f == NULL)
    {
        return -1;
    }
    else
    {
        head->next;
        while(!feof(f))
        {
            fscanf(f, "%s %s %d", temp.ime, temp.prezime, &temp.godinaRodenja);
            InsertAfter(head, temp);
        }
        fclose(f);
        return 0;
    }
}