Cod sursa(job #3161351)

Utilizator tomavladnicolae@gmail.comTomavlad [email protected] Data 26 octombrie 2023 18:22:28
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 fin("ciur.in");
ofstream fout("ciur.out");
bitset<2000003> ciur;
int main()
{
    int n,cnt=0;
    int i,j;
    fin>>n;
    for(i=2;i*i<=n;i++)
        if(ciur[i]==0)
            for(j=i*i;j<=n;j+=i)ciur[j]=1;
    for(i=2;i<=n;i++)if(ciur[i]==0)cnt++;
    fout<<cnt;
    return 0;
}