Cod sursa(job #2749669)

Utilizator proflaurianPanaete Adrian proflaurian Data 7 mai 2021 18:14:33
Problema Ciurul lui Eratosthenes Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.35 kb
Raporteaza aceasta sursa 
#include <bits/stdc++.h>

using namespace std;
ifstream f("ciur.in");
ofstream g("ciur.out");
const int N=2000010;
bitset<N> p;
int n,sol;

int main()
{
    f>>n;
    for(int i=2;i<=n;i++)
        if(!p[i])
        {
            sol++;
            for(int j=2*i;j<=n;j+=i)
                p[j]=1;
        }
    g<<sol;
    return 0;
}