Cod sursa(job #2722534)

Utilizator GeoDinBacauTofan George GeoDinBacau Data 12 martie 2021 22:50:52
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 fcin("ciur.in");
ofstream fcout("ciur.out");

bool ciur[2000007];
int n,nr;

int main()
{
    fcin>>n;
    for(int i=2;i<=n;i++){
        if(ciur[i]==0){
            nr++;
            for(int j=2;i*j<=n;j++)
                ciur[i*j]=1;
        }
    }
    fcout<<nr;
    return 0;
}