Cod sursa(job #306634)

Utilizator bluemoonaiAna Ivan bluemoonai Data 21 aprilie 2009 18:20:31
Problema Ciurul lui Eratosthenes Scor 20
Compilator cpp Status done
Runda Arhiva educationala Marime 0.29 kb
Raporteaza aceasta sursa 
#include<fstream.h>
int main()
{
int N,i,j,k=0;
char c[1000]={0};
ifstream in("ciur.in");
ofstream out("ciur.out");
in>>N;
for (i=2;i*i<=N;i++)
    if (c[i]==0)
	for (j=i*i;j<=N;j+=i)
	   c[j]=1;
for (i=2;i<=N;i++)
   if (c[i]==0) k++;
out<<k;
in.close();
out.close();
return 0;
}