Cod sursa(job #798341)

Utilizator dragos_musanMusan Dragos dragos_musan Data 16 octombrie 2012 13:41:43
Problema Ciurul lui Eratosthenes Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.32 kb
#include<fstream> 

using namespace std;

int main(){ 
	
	ifstream f("ciur.in");
	ofstream g("ciur.out"); 
	long long n,j,i,nr;
	f>>n;
	bool v[2000001]={false}; 
	nr=1; 
	for(i=3;i<=n;i=i+2){ 
		
		if (v[i]==false){ 
			nr++; 
			for (j=i*i;j<=n;j=j+i){ 
				v[j]=true; 
			}
		}
	}
	g<<nr;
	
	return 0;
}