Cod sursa(job #547336)

Utilizator George25Raduta George Cristian George25 Data 6 martie 2011 11:43:18
Problema Ciurul lui Eratosthenes Scor 30
Compilator cpp Status done
Runda Arhiva educationala Marime 0.32 kb
Raporteaza aceasta sursa 
#include<stdio.h>
int a[2000005],t,i,n,j,cnt;
int main(){
	freopen("ciur.in","r",stdin);
	freopen("ciur.out","w",stdout);
	scanf("%d",&n);
	t=n;
	cnt=0;
	for (i=1; i<=n; i++) 
		a[i]=1;
	for (i=2; i<=n; i++){
		if (a[i]){
			cnt++;
			for (j=i+i; j<=n; j+=i) a[j]=0;
		}
	}
	printf("%d",cnt);
	return(0);
}