Cod sursa(job #372735)
Utilizator | Data | 11 decembrie 2009 15:20:44 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.25 kb |
#include<fstream>
using namespace std;
ifstream f("ciur.in");
ofstream g("ciur.out");
char a[2000000];int n,i,j,nr;
int main()
{
f>>n;
for(i=2;i<=n;i++)
if(!a[i])
{nr++;
for(j=2;j<=n/i;j++)
a[i*j]=1;
}
g<<nr;
return 0;
}