Cod sursa(job #1862013)

Utilizator DariusXDXDarius Suditu DariusXDX Data 29 ianuarie 2017 14:35:36
Problema Ciurul lui Eratosthenes Scor 30
Compilator cpp Status done
Runda Arhiva educationala Marime 0.38 kb
#include <iostream>
#include <fstream>
using namespace std;
ifstream in("ciur.in");
ofstream out("ciur.out");
int v[2000000];
int main()
{
    int i,j,x=0,n;
    in>>n;
    for(i=2;i<=n;i++)
    {
        if(v[i]==0)
        for(j=i+i;j<=n;j=j+i)
        v[j]=1;
    }
    for(i=2;i<=n;i++)
    {
        if(v[i]==0)
        x++;
    }
    out<<x;
    return 0;
}