Cod sursa(job #2022214)

Utilizator raduandreiRadu Andrei raduandrei Data 15 septembrie 2017 23:18:51
Problema Ciurul lui Eratosthenes Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.35 kb
Raporteaza aceasta sursa 
#include <iostream>
#include <fstream>
using namespace std;
ifstream in ("ciur.in");
ofstream out("ciur.out");
char c[20000001];
int main()
{
    unsigned long long i,n,j,k=0;
    in>>n;
    for(i=2; i<=n; ++i)
    if(c[i]==0)
    for(j=2; i*j<=n; ++j)
    c[i*j]=1;
    for(i=2; i<=n; ++i) if(c[i]==0) k++;
    out<<k;
        return 0;
}