Cod sursa(job #261789)

Utilizator luci92bestFainisi Lucian Constantin luci92best Data 18 februarie 2009 19:29:31
Problema Ciurul lui Eratosthenes Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.3 kb
Raporteaza aceasta sursa 
#include<fstream.h>
#define  NM 2000000

int main(){
char v[NM+1]={0};
int i,j,n,p;
ifstream fin("ciur.in");
ofstream fout("ciur.out");
fin>>n;
v[1]=1;
for(i=2;i<=n/2;i++)
		if(v[i]==0)
			for(j=2;j*i<=n;j++)
				v[i*j]=1;

p=0;
for(i=2;i<=n;i++) if(v[i]==0) p++;
fout<<p;
return 0;
}