Cod sursa(job #352457)
Utilizator | Data | 1 octombrie 2009 21:20:57 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.35 kb |
#include <fstream>
using namespace std;
ifstream f ("ciur.in");
ofstream g ("ciur.out");
int n, nr;
char v[2000001];
int main()
{ f >> n;
for (int i=3; i<=n; i+=2)
if (!v[i])
{ nr++;
for (int j=i*2; j<=n; j+=i)
v[j]=1;
}
g << nr+1 ;
return 0;
}