/* ==================================================================== */
void Eratosthenes(BitArray_t arr)
{
SetBit(arr, 0, 1);
SetBit(arr, 1, 1);
size_t i_stop = ceil(sqrt(BitArraySize(arr)));
for (size_t i = 2; i <= i_stop; ++i) {
if (!GetBit(arr, i)) {
for (size_t ii = 2 * i; ii < BitArraySize(arr); ii += i) {
SetBit(arr, ii, 1);
}
}
}
}
static void Eratosthenes(BitArray_t pole)
{
unsigned long long i,n;
for (i = 2; i<= sqrt(BitArraySize(pole)) ; i++) // od 2 do sqrt(N)
{
if (GetBit(pole,i) == 0)
for (n = 2; n*i <= (BitArraySize(pole)); n++)
{
SetBit(pole, i*n,1); // "vyskrta nasobky prvocisla"
}
}
return;
}
void Eratosthenes(BitArray_t pole)
{
double upToSqrt = sqrt(BitArraySize(pole));
for(int j = 2; j < upToSqrt; ++j)
{
if(GetBit(pole, j) == 0)
{
for(int i = j*2; i < BitArraySize(pole); i += j)
{
SetBit(pole, i, 1);
}
}
}
}
/*
* Set 0 on primary bits in given BitArray via Eatosthenes algorithm
*
* @param pole BitArray on which
*/
void Eratosthenes(BitArray_t pole)
{
unsigned long N = BitArraySize(pole);
double limit = sqrt(N);
for(unsigned long i = 2; i < limit; i++)
{
if(GetBit(pole,i) == 0)
{
for(unsigned long n = 2; n*i < N; n++)
{
SetBit(pole,n*i,1);
}
}
}
}
