Cod sursa(job #1860821)
Utilizator | Data | 28 ianuarie 2017 13:31:58 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.33 kb |
#include <fstream>
using namespace std;
long long i,j,n,k;
bool t[2000002];
int main() {
ifstream cin("ciur.in");
ofstream cout("ciur.out");
cin>>n;
for (i=2; i<=n; i++)
if (!t[i])
for (j=2; j<=n/i; j++)
t[i*j]=true;
for (i=2; i<=n; i++)
if (!t[i]) k++;
cout<<k;
}