Cod sursa(job #665307)

Utilizator MultiHackRaul Iulian MultiHack Data 21 ianuarie 2012 22:06:10
Problema Ciurul lui Eratosthenes Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.27 kb
#include<fstream>
using namespace std;
char v[2000001];
int n,cnt,i,j;
int main()
{
	ifstream fin("ciur.in");
	ofstream fout("ciur.out");
	fin>>n;
	cnt=1;
	for(i=3;i<=n;i+=2)
		if(!v[i])
		{
			for(j=2;j*i<=n;++j)
				v[i*j]=1;
			++cnt;
		}
	fout<<cnt;
}