Cod sursa(job #886569)
Utilizator | Data | 22 februarie 2013 23:50:01 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.29 kb |
#include <fstream>
using namespace std;
ifstream fin("ciur.in");
ofstream fout("ciur.out");
bool v[2000001];
int nr,n,i,x;
int main()
{
fin>>n;
for (i=2;i<=n;i++)
{
if (v[i]) continue;
nr++;
for (x=2*i;x<=n;x=x+i) v[x]=1;
}
fout<<nr;
}