Cod sursa(job #679511)
Utilizator | Data | 13 februarie 2012 13:20:59 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.31 kb |
#include<fstream>
using namespace std;
long long i,n,j,c;
bool v[2000002];
int main()
{
ifstream fin("ciur.in");
ofstream fout("ciur.out");
fin>>n;
for (i=2;i<=n;i++)
v[i]=1;
for (i=2;i<=n;i++)
if (v[i]==1)
{
c++;
for(j=i+i;j<=n;j=j+i)
v[j]=0;
}
fout<<c;
return 0;
}