char *b1 = new char[dlugosc_genotypu], *b2=b1;
int flag=1;
for (i = 0; i < dlugosc_genotypu; i++)
{
    if( ((float)rand()/(RAND_MAX + 1.0))< wsk_pop->prawd_pkt_krzyzowania )
        flag ^= 1;
    *b2++ = flag;
}

b2 = b1;
for (i=0;i<dlugosc_genotypu;i++)
{
    if (*b2++)
    {
        flag = *genotyp1;
        *genotyp1++ = *genotyp2;
        *genotyp2++ = flag;
    } else {
        genotyp1++;
        genotyp2++;
    }
}