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

using namespace std;

const int N = 16000; // Given that this particular machine has 32-bit storage
                     // elements and we want to process 1000 elements worth of bits.
                     // Changed to 16000 from 32000 because I lose the first 14
                     // lines of output and I'm not about to chase it down!
const int bitsPerInteger = 32;
const int nSetsOf32Ints = N / bitsPerInteger;
/*
Functions for dealing with bits and individual entities
*/
int isSet (int bitNumber);  
void clearBit (int bitNumber);

struct sieve_of_Eratosthenes 
{
   unsigned
   b0:1, b1:1, b2:1, b3:1, b4:1, b5:1, b6:1, b7:1, b8:1, b9:1, b10:1, b11:1,
   b12:1, b13:1, b14:1, b15:1, b16:1, b17:1, b18:1, b19:1, b20:1, b21:1,
   b22:1, b23:1, b24:1, b25:1, b26:1, b27:1, b28:1, b29:1, b30:1, b31:1;

} sieve [nSetsOf32Ints];

int main (void)
{
    int i, j, printoutCount = 0;
    int *mess;

    /* 
    Initialize that sucker by brute force
    */
    for (i = 0; i < nSetsOf32Ints; i++)
    {
        mess = (int *) &sieve [i];
        *mess = 0xffffffff;
    }
    cout << 2 << ", ";
    printoutCount++;
    for (i = 3; i < N; i++)
    {
        if (i % 2) // Ignore all even number markers
        {
            if (isSet (i))  // Lowest 'marked' location.
            {
                cout << i << ", ";
                if (printoutCount++ == 10)
                {
                    cout << endl;
                    printoutCount = 0;
                }
                j = i;
                while (j <= (N - i))    // Subsequent locations to be processed
                {
                      j += i;           // Multiples of what 'i' is right now
                      clearBit (j);
                }
            }
        }
    }
    cout << endl;
    system ("pause");
    return 0;
}
void clearBit (int bit2clear)
{
    int targetInteger;
    int targetBit;
    int clearMask;
    int *mess;
    
    targetInteger = bit2clear / bitsPerInteger;
    targetBit = bit2clear % bitsPerInteger;
    clearMask = 1;
    clearMask <<= targetBit - 1;
    mess = (int *) &sieve [targetInteger];
    *mess &= ~clearMask;
}
int isSet (int bit2test)
{
    int targetInteger;
    int targetBit;
    int peepMask;
    int *mess;

    targetInteger = bit2test / bitsPerInteger;
    targetBit = bit2test % bitsPerInteger;
    peepMask = 1;
    peepMask <<= targetBit - 1;
    mess = (int *) &sieve [targetInteger];
    if (*mess & peepMask) return true; else return false;
}