Cod sursa(job #1338898)
Utilizator | Data | 10 februarie 2015 15:10:29 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 30 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.28 kb |
#include<fstream>
using namespace std;
int n,n1[2000001],i,j;
ifstream fin("ciur.in");
ofstream fout("ciur.out");
int main()
{
fin>>n;
for(i=2;i<=n;++i)if(n1[i]==0)for(j=i;j<=n/i;++j)n1[i*j]=1;j=0;
for(i=2;i<=n;++i)if(n1[i]==0)++j;fout<<j;
return 0;
}