에라토스테네스의 체 C++ 코드

https://www.acmicpc.net/problem/2960

#include <iostream>
#include <string>
#include <istream>
#include <vector>
#include <algorithm>
using namespace std;
bool check[1000001];



int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    int n, k;
    cin >> n >> k;
    int count = -1;

    for (int i = 2; i <= n; i++) {

        if (check[i] == false) {

            for (int j = i; j <= n; j += i) {
                if (check[j] == false) {
                    check[j] = true;
                    k--;
                    count = j;

                }
                if (k == 0) {
                    cout << count;
                    break;
                }
            }
        }
        
    }




    return 0;
}