Cod sursa(job #2788194)
Utilizator | Andrei Ardeleanu Andrei2138 | Data | 25 octombrie 2021 11:32:33 |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 0 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva educationala | Marime | 0.53 kb |
#include <fstream>
#include <bitset>
using namespace std;
const int NMAX=2e6;
bool c[1+NMAX];
int main()
{
ifstream in (ciur.in);
ofstream out (ciur.out);
int n;
in>>n;
in.close();
for(int i = 2 ; i<=n ;i++)
{
if(!c[i])
{
for(int j = i*i ; j<+=n ; j+= i)
{
c[j] = true;
}
}
}
int nr = 0;
for(int i = 2 ; i<=n; i++ )
{
if( !c[i])
{
nr++;
}
}
out<<nr;
return 0;
}