Cod sursa(job #2094422)
Utilizator | Tepes Alexandru Eclipse | Data | 25 decembrie 2017 20:35:31 |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 30 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.48 kb |
#include <iostream>
#include <fstream>
#define dMAX 2000001
using namespace std;
int counter, N;
bool prime[dMAX];
ifstream fin("ciur.in");
ofstream fout("ciur.out");
int main()
{
int i, j;
fin >> N;
prime[1] = true;
for (i = 2; i <= N; i++) {
if (!prime[i]) {
counter++;
for (j = i; j * i <= N; j++) {
prime[j * i] = true;
}
}
}
fout << counter;
return 0;
}