Cod sursa(job #461774)

Utilizator crisvirusDutescu Cristian crisvirus Data 8 iunie 2010 16:34:02
Problema Ciurul lui Eratosthenes Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.31 kb
Raporteaza aceasta sursa 
#include<stdio.h>
bool c[2000001];
int i,j,n,p;
int main()
{
	
	freopen("ciur.in","r",stdin);
	freopen("ciur.out","w",stdout);
	scanf("%d",&n);
	c[1]=true;
	for(i=2;i*i<=n;++i)
		if(!c[i])
			for(j=i*i;j<=n;j+=i)
				c[j]=true;
	for (i=2;i<=n;++i)
			if(!c[i])
				++p;
	printf("%d",p);
	return 0;
}