Cod sursa(job #960764)

Utilizator TarabanDragosTaraban Dragos-Petru TarabanDragos Data 11 iunie 2013 02:41:39
Problema Ciurul lui Eratosthenes Scor 30
Compilator cpp Status done
Runda Arhiva educationala Marime 0.35 kb
Raporteaza aceasta sursa 
#include<cstdio>
long int n,i,j,v[2000005],np;
FILE *f,*g;
int main(){
	f=fopen("ciur.in","r");
	g=fopen("ciur.out","w");
	fscanf(f,"%ld",&n);
	for(i=2;i<=n;i++){
		v[i]=1;
	}
	np=0;
	for(i=2;i<=n;i++){
		if(v[i]==1){
			for(j=2*i;j<=n;j+=i){
				v[j]=0;
			}
			np++;
		}
	}
	fprintf(g,"%ld",np);
	fclose(f);
	fclose(g);
return 0;
}