sàng nguyên tố

#include <iostream>
#include <bits/stdc++.h>

using namespace std;

void sangnguyento(int n)
{
    bool prime[n+1];
    for (int i=2;i<=n;i++)
        prime[i]=true;
    for (int i=2;i*i<=n;i++)
        if (prime[i]==true)
        for (int j=i*i;j<=n;j+=i)
        prime[j]=false;
    for (int i=2;i<=n;i++)
        if (prime[i]==true)
        cout<<i<<" ";
}

int main()
{
    int n;
    cin>>n;
    sangnguyento(n);
    return 0;
}