Cod sursa(job #2661819)
Utilizator | Data | 22 octombrie 2020 19:17:34 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 50 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva educationala | Marime | 0.42 kb |
#include <fstream>
using namespace std;
ifstream fin ("ciur.in");
ofstream fout ("ciur.out");
bool v[2000001];
int main()
{
int n, i, j, nr = 2;
fin >> n;
for(i = 1; i <= n; i++)
{
for(j = nr*2; j <= n; j += nr)
v[j] = 1;
nr++;
}
nr = 0;
for(i = 2; i <= n; i++)
{
if(v[i] == 0)
nr++;
}
fout << nr;
return 0;
}