Cod sursa(job #2615301)
Utilizator | Sergiu Mihaila MSergiu_01 | Data | 14 mai 2020 11:32:14 |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva educationala | Marime | 0.51 kb |
#include <fstream>
#define NMAX 2000001
using namespace std;
ifstream fin("ciur.in");
ofstream fout("ciur.out");
bool ciur[NMAX];
int n;
int CIUR(int n)
{
int i, counter = 0;
ciur[1] = 1;
ciur[0] = 1;
for(i = 2; i <= n; i++)
{
if(ciur[i] == 0)
{
for(int j = 2; j*i <= n; j++)
ciur[i*j] = 1;
counter++;
}
}
return counter;
}
int main()
{
fin >> n;
fout << CIUR(n);
return 0;
}