Cod sursa(job #659064)
Utilizator | Data | 9 ianuarie 2012 23:04:21 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 30 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.3 kb |
#include <fstream>
using namespace std;
int p[675000],i,j,nr,n;
int main ()
{
ifstream f ("ciur.in");
ofstream g ("ciur.out");
f >>n;
for (i=2; i<=n; i++)
p[i]=1;
for (i=2; i<=n; i++)
if (p[i])
{
nr++;
for (j=i+i; j<=n; j+=i)
p[j]=0;
}
g <<nr;
return 0;
}