Cod sursa(job #1108481)
Utilizator | Data | 15 februarie 2014 19:05:03 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.3 kb |
#include <fstream>
using namespace std;
char v[2000005];
int main()
{
int n, nr = 1;
ifstream cin("ciur.in");
ofstream cout("ciur.out");
cin >> n;
for (int i = 3; i <= n; i += 2)
if (v[i] == 0)
{
nr++;
for (int j = 3 * i; j <= n; j += 2 * i)v[j] = 1;
}
cout << nr;
return 0;
}