Cod sursa(job #2347465)

Utilizator Codrut112Codrut Copas Codrut112 Data 18 februarie 2019 20:13:52
Problema Ciurul lui Eratosthenes Scor 30
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.3 kb
Raporteaza aceasta sursa 
#include <iostream>
#include <cmath>
#include <fstream>
using namespace std;
int n,x,i,nr;
bool v[1000000];
int main()
{ifstream f("ciur.in");
ofstream g("ciur.out");
    f>>n;
for(i=2;i*i<=n;i++){
if(v[i]==0) {
for(x=i*i;x<=n;x+=i){v[x]=1;}
}
}for(i=2;i<=n;i++){
if(v[i]==0) nr++;
}g<<nr;
}