Cod sursa(job #530088)

Utilizator dianapavalucPavaluc Diana dianapavaluc Data 6 februarie 2011 20:14:19
Problema Ciurul lui Eratosthenes Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.35 kb
Raporteaza aceasta sursa 
#include<iostream>
#include<fstream>
#define N 2000001
using namespace std;
ifstream f("ciur.in");
ofstream g("ciur.out");
long long i,j,n,t;
char v[N];
int main()
{ f>>n;
  for(i=2;i*i<=n;i++)
    if(v[i]==0)
        for(j=i;i*j<=n;j++)v[i*j]=1;
  for(i=2;i<=n;i++)
    if(v[i]==0)t++;
  g<<t;
    f.close();
    g.close();
    return 0;
}