埃拉托斯特尼——筛法

#include //埃拉托斯特尼——筛法

#include

#include

using namespace std;

int main()

{

int const max_number(100);

int const max_test((int)sqrt((double)max_number));

bitset numbers;  //101个0!

numbers.set(); //101个1!

//numbers[0] //不理他

numbers[1] = 0;

for(int i(1);i != max_test;i++)

{

if(numbers[i]){

//筛掉倍数，

for（int j=i*(2)i;j

{

numbers[j] = 0;

}

}

}

cout<< "the number of primes less than" <

            <<"is"<

for(int i(1)i!=max_number+1;i++)

{

if(numbers[i])  cout << i <<","

}

cout << endl;

return 0;

}