Cod sursa(job #301462)
| Utilizator |  Pop Andreea Andreiutza |
Data | 8 aprilie 2009 11:22:29 |
|---|---|---|---|
| Problema | Ciurul lui Eratosthenes | Scor | 100 |
| Compilator | cpp | Status | done |
| Runda | Arhiva educationala | Marime | 0.32 kb |
#include<fstream.h>
using namespace std;
char prim[2000010];
long nr=0, i, j, n;
ifstream f("ciur.in");
ofstream g("ciur.out");
int main ()
{ f>>n; prim[1]=0;
for(i=2;i<=n;i++)
prim[i]=1;
for(i=2;i<=n;i++)
if(prim[i])
for(j=i+i;j<=n;j+=i)
prim[j]=0;
for(i=1;i<=n;i++)
if(prim[i]) nr++;
g<<nr;
return 0;
}
