Cod sursa(job #166822)

Utilizator slayer4uVictor Popescu slayer4u Data 28 martie 2008 15:37:55
Problema Ciurul lui Eratosthenes Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.33 kb
Raporteaza aceasta sursa 
#include <stdio.h>

long num, i, j, n;
char v[2000010];

int main()
{
	freopen ("ciur.in", "rt", stdin);
	freopen ("ciur.out", "wt", stdout);

	scanf("%ld", &n);

	for (i = 2; i <= n; i++)
	{
		if (!v[i])
		{
			num ++;
			for (j = i + i; j <= n; j += i)
				v[j] = 1;
		}
	}

	printf("%ld\n", num);

	return 0;
}