Cod sursa(job #698131)

Utilizator bogdan211Nastasa Bogdan bogdan211 Data 29 februarie 2012 12:30:49
Problema Ciurul lui Eratosthenes Scor 30
Compilator cpp Status done
Runda Arhiva educationala Marime 0.28 kb
Raporteaza aceasta sursa 
#include<fstream>
#include<iostream>
using namespace std;
ifstream f("ciur.in");
ofstream q("ciur.out");
int a[2000000];
int main ()
{
	long long i,j,n,s=1;
	f>>n;
	for(i=3;i<=n;i=i+2)
	   if(a[i]==0)
		{  s++;
			for(j=i*i;j<=n;j=i+j)
			   a[j]=1;
		}
       q<<s;
}