Cod sursa(job #280818)

Utilizator sicazoRLazar Marius sicazoR Data 13 martie 2009 16:23:49
Problema Ciurul lui Eratosthenes Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.34 kb
Raporteaza aceasta sursa 
#include<fstream>
#include<math.h>
using namespace std;
int main (){
	int n,i,j,ok,ct=0;
	char x[2000001];
	ifstream f("ciur.in");
	ofstream g("ciur.out");
	f>>n;
	for(i=2;i<n;i++)
		x[i]=1;
	for(i=2;i<=n;i++)
		if(x[i]!=0){
			ct++;
			for(j=i+i;j<=n;j=j+i)
				x[j]=0;
		}
		
	g<<ct;
	f.close();
	g.close();
	return 0;
}