Cod sursa(job #572976)

Utilizator noruIlies Norbert noru Data 5 aprilie 2011 19:38:09
Problema Ciurul lui Eratosthenes Scor 70
Compilator cpp Status done
Runda Arhiva educationala Marime 0.31 kb
Raporteaza aceasta sursa 
#include<fstream.h>
bool v[2000001];
int main()
{
	ifstream f("ciur.in");
	ofstream g("ciur.out");
	int n,i,j,k=0;
	v[1]=0;
	f>>n;
	for (i=2;i<=n;i++)
		v[i]=1;
	for (i=2;i*i<=n;i++)
		for (j=2;j*i<=n;j++)
			if (v[i*j]==1) v[i*j]=0;
	for (i=1;i<=n;i++)
		if (v[i]==1) k++;
	g<<k;
	return 0;
}