Cod sursa(job #2052264)

Utilizator NicuPopPop Nicolae NicuPop Data 30 octombrie 2017 12:34:31
Problema Ciurul lui Eratosthenes Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.35 kb
#include <iostream>
#include <fstream>
using namespace std;
bool a[2000005];
int main()
{int n,i,j,k=0;
ifstream f("ciur.in");
ofstream g("ciur.out");
 f>>n;
 for(i=2;i<=n;i++)
    a[i]=1;
 for(i=2;i<=n;i++)
    if(a[i])
       for(j=2*i;j<=n;j+=i)
         a[j]=0;
 for(i=1;i<=n;i++)
      if(a[i]==1)
         k++;
 g<<k;



}