Cod sursa(job #539585)

Utilizator cozminasandica cosmina cozmina Data 23 februarie 2011 08:43:38
Problema Ciurul lui Eratosthenes Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 0.33 kb
Raporteaza aceasta sursa 
#include<fstream.h>
ifstream fin("fibonacci.in");
ofstream fout("fibonacci.out");
unsigned char a[2000000];
long n;
int main()
{
	long i,j,nr=0;
	fin>>n;
	a[0]=1;
	a[1]=1;
	for(i=2;i*i<=n;i++)
		if(a[i]==0)
			for(j=2*i;j<=n;j=j+i)
				a[j]=1;
			for(i=2;i<=n;i++)
				if(a[i]==0)nr++;
			fout<<nr;
				return 0;
}