Cod sursa(job #1241409)

Utilizator standragos98Stan Dragos standragos98 Data 13 octombrie 2014 15:10:58
Problema Ciurul lui Eratosthenes Scor 90
Compilator cpp Status done
Runda Arhiva educationala Marime 0.34 kb
#include <cmath>
#include <fstream>
using namespace std;

bool a[2000000];

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