Prisustvashti_otsutvashti

#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);
}

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;
    setBit(&prisustviq, 1);
    setBit(&prisustviq, 3);
    setBit(&prisustviq, 0);
    //eraseBit(&prisustviq, 3);
    printf("%d\n", onesCount(prisustviq));
    return 0;
}