Cod sursa(job #2165881)

Utilizator tuddor1234Turdasan Tudor tuddor1234 Data 13 martie 2018 14:12:38
Problema Ciurul lui Eratosthenes Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.34 kb
Raporteaza aceasta sursa 
#include <bits/stdc++.h>
#include <string>
using namespace std;

ifstream fin ("ciur.in");
ofstream fout ("ciur.out");

int n;

bool v[2000002];
int x=0;
int main()
{
    fin>>n;
    for(int i=2;i<=n;i++)
    if(v[i]==0)
    {
        x++;
        for(int j=i*2;j<=n;j+=i)
            v[j]=1;
    }
    fout<<x;
    return 0;
}