Cod sursa(job #648985)

Utilizator roots4Irimia Alexandru Gabriel roots4 Data 14 decembrie 2011 21:48:10
Problema Ciurul lui Eratosthenes Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.31 kb
Raporteaza aceasta sursa 
#include <stdio.h>
int n , k , i , j;
char V[2000005];
int main(){
	freopen("ciur.in","r",stdin);
	freopen("ciur.out","w",stdout);
	scanf("%d",&n);
	k=n-1;
	for(i=2;i<=n/2;i++){
		if(V[i]==0){
			for(j=2;j<=n/i;j++){
				if(V[i*j]==0)
					k--;
				V[i*j]=1;
			}
		}
	}
	printf("%d",k);
	return 0;
}