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

#define ANZ_SCHUELER 30

typedef struct
{
    char name[10];
    char vorname[10];
    unsigned note;
} Person;

int eingabe(Person *p, int i)
{
    printf("---Eingabe des %d. Schuelers----\n", i);
    printf("Name: ");
    fgets(p->name, sizeof(p->name), stdin);
    if (p->name[strlen(p->name) - 1] == '\n')
    {
        p->name[strlen(p->name) - 1] = '\0';
    }

    if (strlen(p->name) == 0)
    {
        return 0;
    }

    printf("Vorname: ");
    fgets(p->vorname, sizeof(p->vorname), stdin);
    if (p->vorname[strlen(p->vorname) - 1] == '\n')
    {
        p->vorname[strlen(p->vorname) - 1] = '\0';
    }

    if (strlen(p->vorname) == 0)
    {
        return 0;
    }

    printf("Note: ");
    if (scanf("%u", &p->note) != 1 || p->note < 0 || p->note > 6)
    {
        return 0;
    }
    while (getchar() != '\n');

    return 1;
}

float durchschnittsnote(Person *n, int anzahl)
{
    float sum = 0;
    float durchschnitt;
    for (int i = 0; i < anzahl; ++i)
    {
        sum += n[i].note;
    }
    durchschnitt = sum / anzahl;
    return durchschnitt;

}

void notenspiegel(Person *n, int anzahl)
{
    int notenHaeufigkeit[6] = {0};

    for (int i = 0; i < anzahl; ++i)
    {
        notenHaeufigkeit[n[i].note - 1]++;
    }

    printf("\nNotenspiegel:\n");
    for (int i = 0; i < 6; ++i)
    {
        printf("Note %d: ", i + 1);
        for (int j = 0; j < notenHaeufigkeit[i]; ++j)
        {
            printf("*");
        }
        printf("\n");
    }
}

void printListe(Person *liste, int anzahl)
{
    printf("Name \t\t ,Vorname \t\t ,Note ");
    printf("\n------------------------------------------------------------------------\n");
    for (int i = 0; i < anzahl; ++i)
    {
        if (strlen(liste[i].name) > 0)
        {
            printf("%s \t\t ,%s \t\t ,%u\n", liste[i].name, liste[i].vorname, liste[i].note);
        }
    }
}

int main()
{
    Person schueler[ANZ_SCHUELER];
    int i;

    for (i = 0; i < ANZ_SCHUELER; ++i)
    {
        if (!eingabe(&schueler[i], i + 1))
        {
            break;
        }
    }

    printListe(schueler, i);
    printf("Durchschnittsnote = %2.f ", durchschnittsnote(schueler, i));
    notenspiegel(schueler,i);
    return 0;
}