Cod sursa(job #828823)

Utilizator Stefanescu_MihaiStefanescu Mihai-Nicolae Stefanescu_Mihai Data 4 decembrie 2012 15:14:58
Problema Ciurul lui Eratosthenes Scor 30
Compilator cpp Status done
Runda Arhiva educationala Marime 0.33 kb
Raporteaza aceasta sursa 
#include <fstream>
using namespace std;
unsigned char a[2000009];
int main()
{
	unsigned int m,y,i;
	double n;
	ifstream f1("ciur.in");
	f1>>n;
	m=0;
	f1.close();
	for (y=2;y<=n;y++)
		if (!a[y])
		{
			for (i=y+y;i<=n;i+=y)
				if (!a[i]) a[i]=1;
			m++;
		}
	ofstream f2("ciur.out");
	f2<<m;
	f2.close();
	return 0;
}