Cod sursa(job #394161)
Utilizator | Rector George georgel | Data | 10 februarie 2010 17:18:33 |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 0 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.44 kb |
#include<fstream>
#define Max 2000001
using namespace std;
long n,p;
char c[Max];
void umplere(char a)
{
long i,x;
x = a-'0';
for(i = x+1; i <= n; i++)
{
if(i%x == 0)
{
c[i] = 1;
}
}
}
int main()
{
ifstream fin("ciur.in");
ofstream fout("ciur.out");
long i;
fin>>n;
for(i = 2; i <= n ;i++)
if(c[i] == 0)
{
p = p+1;
umplere(i);
}
fout<<p<<"\n";
fin.close();
fout.close();
return 0;
}