Cod sursa(job #731333)

Utilizator Vladinho97Iordan Vlad Vladinho97 Data 7 aprilie 2012 21:42:53
Problema Ciurul lui Eratosthenes Scor 30
Compilator cpp Status done
Runda Arhiva educationala Marime 0.3 kb
Raporteaza aceasta sursa 
#include<fstream>
using namespace std;
long long i,j,n,p[1000001],nr=1;
int main()
{
	ifstream f("ciur.in");
	ofstream g("ciur.out");
	f>>n;
	for(i=1;i<=(n-1)/2;i++)
		if(p[i]==0)
			for(j=i*2*(i+1);j<=(n-1)/2;j+=i*2+1)
				p[j]=1;
	for(i=1;i<=(n-1)/2;i++)
		if (p[i]==0) 
			nr++;
	g<<nr;
}