Cod sursa(job #1311463)

Utilizator RaulBodrogeanMircea-Raul Bodrogean RaulBodrogean Data 8 ianuarie 2015 11:28:30
Problema Ciurul lui Eratosthenes Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 0.27 kb
#include <iostream>

using namespace std;
int main() {
bool a[2000001];
int nr=0, n, i, j;
cin>>n;
for (i=2;i<=n;i++)
  a[i]=1;
for (i=2;i<=n/2;i++)
 if (a[i])
  for (j=i;j<=n/i;j++)
     a[i*j]=0;
for (i=2;i<=n;i++)
  if (a[i]) nr++;
cout<<nr;
return 0;
}