PracticeDayFourExercise1

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

void setBit(int* mask, int n)
{
    *mask |= (1 << n);
}

void eraseBit(int* mask, int n)
{
    *mask &= ~(1 << n);
}

int isSet(int mask, int n)
{
    return mask & (1 << n);
}

//HW
void funkci(int mask){
    for (int i = 0; i < sizeof(int) * 8; i++)
    {
        if (isSet(mask, i))
        {
            printf("%d ", i);
        }
    }
}

//HW
void funkti(int mask){
    for (int i = 0; i < sizeof(int) * 8; i++)
    {
        if (!isSet(mask, i))
        {
            printf("%d ", i);
        }
    }
}

int onesCount(int mask)
{
    int count = 0;
    for (int i = 0; i < sizeof(int) * 8; i++)
    {
        if (isSet(mask, i))
        {
            count++;
        }
    }
    return count;
}

int zerosCount(int mask)
{
    return sizeof(int) * 8 - onesCount(mask);
}

int main()
{
    int prisustviq = 0;
    int option;
    while (1)
    {
        printf("1. ADD PRESENCE\n");
        printf("2. ADD ABSENCE\n");
        printf("3. INFORMATION\n");
        printf("4. EXIT\n");
        scanf("%d", &option);
        if (option == 1)
        {
            int n;
            printf("Enter student`s number: ");
            scanf("%d", &n);
            if(n >= 0 && n <= 32)
            {
                 setBit(&prisustviq, n);
            }
            else
            {
                 printf("    -ERROR-   \n Invalid option! \n");
            }
        }
        else if (option == 2)
        {
            int n;
            printf("Enter student`s number: ");
            scanf("%d", &n);
            if(n >= 0 && n <= 32)
            {
                 eraseBit(&prisustviq, n);
            }
            else
            {
                 printf("    -ERROR-   \n Invalid option! \n");
            }
        }
        else if (option == 3)
        {
            printf("1. OVERALL CLASS INFORMATION\n");
            printf("2. INFORMATION BY NUMBERS\n");
            int n;
            scanf("%d", &n);
            if(n == 1)
            {
                printf("Total number of presence students: %d\n", onesCount(prisustviq));
                printf("Total number of absence students: %d\n", zerosCount(prisustviq));
            }
            else if(n == 2)
            {
                printf("Presence students by number: ");
                funkci(prisustviq);
                printf("\n");

                printf("Absence students by number: ");
                funkti(prisustviq);
                printf("\n");
            }
            else
            {
                printf("    -ERROR-   \n Invalid option! \n");
            }
        }
        else if (option == 4)
        {
            break;
        }
        else
        {
            printf("    -ERROR-   \n Invalid option! \n");
        }
    }
    return 0;
}