Sieve of Eratosthenes

In this lesson, we'll learn about the Sieve of Eratosthenes and some of its applications. We will solve the following base problem:

Given two numbers $n, q$ and a sequence $v$ of $q$ integers $(2 \leqslant v_i \leqslant n)$, for every number in this sequence, you need to say whether it is prime or not

As we saw in the previous lesson, we can answer whether $v$ is prime in $O(\sqrt n)$. Then using the method we already know, our complexity will be $O(q\sqrt n)$.

#include <iostream>
using namespace std;

int main()
{
	int q, n;
	cin >> q >> n;

	for (int i = 0; i < q; i++)
	{
		int v;
		cin >> v;