sieve.cpp

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#include <vector>
#include <iostream>
 
#include <examples.h>
    
int main ()
{
 
    std::cout << "Prime Sieve program, a test of vectors" << std::endl;
 
    // Create a sieve of bits, initially set to 1.
    const int sievesize = 100;
    std::vector<int, std::allocator<int> > sieve ((std::size_t)sievesize, 1);
 
    // At positions that are multiples of i, set value to zero.
    for (int i = 2; i * i < sievesize; i++)
        if (sieve[i])
            for (int j = i + i; j < sievesize; j += i)
                sieve[j] = 0;
 
    // Now output all the values that are still set.
    for (int j = 2; j < sievesize; j++)
        if (sieve[j]) 
            std::cout << j << " ";
    
    std::cout << std::endl << "End of Prime Sieve program" << std::endl;
 
    return 0;
}