Cod sursa(job #302840)
Utilizator | Data | 9 aprilie 2009 12:28:55 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.31 kb |
#include<fstream>
using namespace std;
int n,k;
char prim[2000005];
int main(void)
{int i,j;
ifstream f("ciur.in");
ofstream g("ciur.out");
f>>n;
for(i=2;i<=n;++i)
prim[i]=1;
for(i=2;i<=n;++i)
if(prim[i])
{k=k+1;
for(j=i+i;j<=n;j=j+i)
prim[j]=0;
}
g<<k;
return 0;
}