Cod sursa(job #2365766)

Utilizator Vlad29Graure Vlad-Stefan Vlad29 Data 4 martie 2019 16:18:15
Problema Ciurul lui Eratosthenes Scor 30
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.41 kb
#include <iostream>
#include <fstream>
using namespace std;
ifstream in("ciur.in");
ofstream out("ciur.out");
int n,s;
bool v[2000001];
int main()
{
    in>>n;
    for(int i=1;i<=n;i++)v[i]=1;
    v[0]=0;
    v[1]=0;
    for(int i=2;i<=n;i++){
        for(int j=i;j*i<=n;j++){
            v[i*j]=0;
        }
    }
    for(int i=1;i<=n;i++){
        if(v[i]==1)s++;
    }
    out<<s;
    return 0;
}