Cod sursa(job #2340440)

Utilizator emiAZemanuel zurini emiAZ Data 10 februarie 2019 14:12:03
Problema Ciurul lui Eratosthenes Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.33 kb
Raporteaza aceasta sursa 
#include <fstream>

using namespace std;
ifstream cin("ciur.in");
ofstream cout("ciur.out");
bool v[20000000];
int main()
{
    int n,i,j,k=0;
    cin>>n;
    for(i=2;i<=n;i++)
        if(v[i]==0)
        for(j=i+i;j<=n;j+=i)
        v[j]=1;
    for(i=2;i<=n;i++)
        if(v[i]==0)k++;
        cout<<k;
    return 0;
}