Cod sursa(job #261773)

Utilizator testtestDan Butuc testtest Data 18 februarie 2009 19:22:57
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;
}