Cod sursa(job #2219507)

Utilizator danielsociuSociu Daniel danielsociu Data 9 iulie 2018 10:09:12
Problema Ciurul lui Eratosthenes Scor 50
Compilator cpp Status done
Runda Arhiva educationala Marime 0.31 kb
Raporteaza aceasta sursa 
#include <fstream>
std::ifstream cin("ciur.in");
std::ofstream cout("ciur.out");
int v[2000005];

int main()
{
    int x,ans=0;
    cin>>x;
    for(int i=2;i<=x;i++)
        if(!v[i]){
            ans++;
            for(int j=i+i;j<=x;j+=i)
                v[j]=1;
    }
    cout<<ans;
    return 0;
}