Cod sursa(job #742729)

Utilizator FlameingoAiordachioaei Marius Flameingo Data 1 mai 2012 09:51:47
Problema Ciurul lui Eratosthenes Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.3 kb
Raporteaza aceasta sursa 
#include<cstdio>
#include<cstring>
using namespace std;
char c[2000001];
int main()
{
	freopen("ciur.in","r",stdin);freopen("ciur.out","w",stdout);
	int n,i,j,s=1;
	scanf("%d",&n);
	for(i=3;i<=n;i+=2)
	{
		if(!c[i])
		{
			s++;
			for(j=i+i;j<=n;j+=i)
				c[j]=1;
		}
	}
	printf("%d",s);
}