Cod sursa(job #679510)
Utilizator | Data | 13 februarie 2012 13:20:13 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.3 kb |
#include <fstream>
using namespace std;
bool v[2000002];
long long i,j,n,c;
int main()
{
ifstream f("ciur.in");
ofstream q("ciur.out");
f>>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;
}
q<<c;
return 0;
}