Cod sursa(job #727315)
Utilizator | Data | 27 martie 2012 21:00:13 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 0 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.64 kb |
# include <iostream>
# include <fstream>
# define Nmax 2000005
using namespace std;
ifstream f ("ciur.in");
ofstream g ("ciur.out");
int N, nrp = 0;
char prim[Nmax];
void ciur (int n)
{
int i,j;
for(i=2; i<=n; i++)
{
prim[i] = 1;
}
for (i=2; i<=n; i++)
{
if (prim[i])
{
++nrp;
for(j=i+i; j<=n; j++)
prim[j] = 0;
}
}
}
inline void citire ()
{
f >> N;
f.close();
}
inline void scriere ()
{
g << nrp << '\n';
g.close();
}
int main ()
{
citire();
ciur(N);
scriere();
return 0;
}