Cod sursa(job #742724)

Utilizator FlameingoAiordachioaei Marius Flameingo Data 1 mai 2012 09:43:37
Problema Ciurul lui Eratosthenes Scor 70
Compilator cpp Status done
Runda Arhiva educationala Marime 0.31 kb
Raporteaza aceasta sursa 
#include<cstdio>
#include<cstring>
using namespace std;
int main()
{
	freopen("ciur.in","r",stdin);freopen("ciur.out","w",stdout);
	int n,i,j,s=1;bool c[2000001];
	scanf("%d",&n);
	memset(c,0,sizeof(c));
	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);
}