Cod sursa(job #543660)
Utilizator | Data | 28 februarie 2011 13:48:38 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 90 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.29 kb |
#include <fstream>
using namespace std;
bool a[2000000];
int main()
{
int n,i,k=0;
ifstream in("ciur.in");
ofstream out("ciur.out");
in>>n;
for(i=2; i<=n; i++)
if(a[i]==false)
{
for(int j=i; j<2000000; j=j+i)
a[j]=true;
k++;
}
out<<k;
return 0;
}