Cod sursa(job #1730040)

Utilizator andreis181andreis181 andreis181 Data 16 iulie 2016 05:22:09
Problema Ciurul lui Eratosthenes Scor 80
Compilator cpp Status done
Runda Arhiva educationala Marime 0.33 kb
Raporteaza aceasta sursa 
#include <iostream>
#include <fstream>
using namespace std;

int n;
char a[2000005];
int main()
{
    ifstream f("ciur.in");
    ofstream g("ciur.out");
    int i,j,nr=1;
    f>>n;
    for(i=3;i<=n;i+=2)
    {
        if(a[i]==0)
            nr++;
        for(j=i+i+i;j<=n;j+=i)
            a[j]=1;
    }
    g<<nr;
}