Cod sursa(job #1337197)
Utilizator | Data | 8 februarie 2015 18:46:29 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 0 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.42 kb |
#include <iostream>
#include <fstream>
using namespace std;
#define MAX_N 2000001
bool ciur[MAX_N],n;
int nr;
ifstream f("ciur.in");
ofstream g("ciur.out");
void compute()
{
long i;
for (i = 2; i <= n; i++)
{
if (!ciur[i])
{
++nr;
for (long j = i + i; j <= n; j = j + i)
{
ciur[j] = true;
}
}
}
}
int main()
{
f >> n;
compute();
g << nr;
f.close();
g.close();
}