Cod sursa(job #264219)
Utilizator | Data | 21 februarie 2009 19:38:02 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.26 kb |
#include<fstream>
using namespace std;
ifstream f("ciur.in");
ofstream g("ciur.out");
int main()
{
long n,i,j;
char v[2000005]={0};
int a=0;
f>>n;
for(i=2;i<=n;i++) if(!v[i]){ ++a; for(j=i+i;j<=n;j+=i) v[j]=1;}
g<<a;
f.close();
g.close();
return 0;}