Cod sursa(job #406745)

Utilizator lucian666Vasilut Lucian lucian666 Data 1 martie 2010 19:22:12
Problema Ciurul lui Eratosthenes Scor 20
Compilator cpp Status done
Runda Arhiva educationala Marime 0.35 kb
Raporteaza aceasta sursa 
#include<iostream>
#include<fstream>
using namespace std;
int main()
{
	int ciur[15000],i,j,n,c=0;
	ifstream fin("ciur.in");
		ofstream fout("ciur.out");
	fin>>n;
	for(i=2;i<=n;i++)
		ciur[i]=1;
	for(i=2;i*i<=n;i++)
		if(ciur[i])
			for(j=2*i;j<=n;j+=i)
				ciur[j]=0;
	for(i=2;i<n;i++)
		if(ciur[i])
					c++;
	 fout<<c;
	return 0;
}