Cod sursa(job #2721385)

Utilizator RobertAcAcatrinei Robert-Marian RobertAc Data 11 martie 2021 19:08:10
Problema Ciurul lui Eratosthenes Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.31 kb
Raporteaza aceasta sursa 
#include <bits/stdc++.h>

using namespace std;
ifstream in("ciur.in");
ofstream out("ciur.out");
int main(){
    int n,nr=0;
    in>>n;
    vector<bool> v(n+1);
    for(int i=2;i<=n;i++){
        if(!v[i]){
            nr++;
            for(int j=2;j*i<=n;j++)v[j*i]=true;
        }
    }out<<nr;

}