Cod sursa(job #381965)
Utilizator | Data | 12 ianuarie 2010 12:06:17 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.26 kb |
#include <fstream.h>
long n,i,j,np;
char v[2000001];
ifstream fin ("ciur.in");
ofstream fout ("ciur.out");
int main ()
{
fin>>n;
for (i=3;i<=n;i=i+2)
if (v[i]==0)
{
np++;
for (j=i+i;j<=n;j=j+i)
v[j]=1;
}
fout<<np+1;
return 0;
}