Cod sursa(job #1977768)
Utilizator | Data | 6 mai 2017 00:56:05 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 50 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.29 kb |
#include <fstream>
int i,j,n,nr;
short f[2000001];
using namespace std;
int main()
{
ifstream in("ciur.in");
ofstream out("ciur.out");
in>>n;
for(i=3;i<=n;i+=2)
for(j=2;i*j<=n;j++)
f[i*j]=1;
for(i=3;i<=n;i+=2)
if(f[i]==0)
nr++;
out<<nr+1;
return 0;
}