Cod sursa(job #1165618)
Utilizator | Data | 2 aprilie 2014 19:43:45 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 30 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.28 kb |
#include <fstream>
using namespace std;
ifstream in("ciur.in");
ofstream out("ciur.out");
int v[2000001];
int main()
{int i,j,n,c=0;
in>>n;
for(i=2;i<=n;i++)
if(v[i]==0)
{c++;
for(j=2*i;j<=n;j=j+i)
v[j]=1;}
out<<c<<endl;
return 0;
}