Cod sursa(job #2273475)

Utilizator borzaalexAlexandru Borza borzaalex Data 31 octombrie 2018 17:13:28
Problema Ciurul lui Eratosthenes Scor 30
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.47 kb
#include <fstream>
#include <cmath>
#include <iostream>
using namespace std;
int n,m,i;
short a[2000005];

    ifstream fin("ciur.in");
    ofstream fout("ciur.out");
int main()
{
    fin>>n;
    a[1]=1;
    for(int i=2;i<=sqrt(n)+1;i++)
        if(a[i]==0)
        for(int j=2;j*i<=n;j++)
        a[i*j]=1;
    int k=0;
    for(int i=1;i<=n;i++)
        cout<<i<<" "<<a[i]<<'\n';
    for(int i=1;i<=n;i++)
        k=k+1-a[i];

    fout<<k;
    return 0;
}