Cod sursa(job #574373)
Utilizator | Data | 7 aprilie 2011 09:24:14 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 60 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.31 kb |
#include<fstream>
using namespace std;
short ok[2000001];
int main()
{int n,i,d,cont=0;
ifstream f1("ciur.in");
ofstream f2("ciur.out");
f1>>n;
for(i=2;i<=n;i++)
{
if(!ok[i])
{for(d=2*i;d<=n;d+=i)
ok[d]=1;
cont++;
}
if(i==n) break;
}
f2<<cont;
return 0;
}