Cod sursa(job #665303)
Utilizator | Data | 21 ianuarie 2012 22:03:35 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 30 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.26 kb |
#include<fstream>
using namespace std;
char v[2000000];
int n,cnt,i,j;
int main()
{
ifstream fin("ciur.in");
ofstream fout("ciur.out");
fin>>n;
for(i=2;i<=n;++i)
if(!v[i])
{
for(j=i*i;j<=n;j+=i)
v[j]=1;
++cnt;
}
fout<<cnt;
}