Cod sursa(job #779337)
Utilizator | Data | 17 august 2012 15:18:41 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 30 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.34 kb |
#include<fstream>
using namespace std;
ifstream in("ciur.in");
ofstream out("ciur.out");
double long a[2000000];
int main ()
{
long i,n,p;
int k=0;
in>>n;
for(i=2;i<=n;i++)
if(a[i]==0)
{ p=2;
while((p*i)<=n)
{
a[p*i]=1;
p++;
}
k++;
}
out<<k;
}