Cod sursa(job #1610781)
Utilizator | Data | 23 februarie 2016 18:46:02 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 30 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.34 kb |
# include <fstream>
# define DIM 2000010
using namespace std;
ifstream fin("ciur.in");
ofstream fout("ciur.out");
int f[DIM],n,nr,i,j;
int main () {
fin>>n;
for(i=2;i<=n;i++){
if(f[i]==0){
nr++;
for(j=2*i;j<=n;j+=i)
f[j]=1;
}
}
fout<<nr<<"\n";
return 0;
}