Cod sursa(job #2452015)

Utilizator vladmotoiVlad Motoi vladmotoi Data 29 august 2019 08:58:02
Problema Ciurul lui Eratosthenes Scor 30
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.32 kb
Raporteaza aceasta sursa 
#include <iostream>
#include <fstream>
using namespace std;
fstream f("ciur.in");
ofstream g("ciur.out");
long long i,n,j,nr;
int main()
{
f>>n;
long long a[n+1];
for (i=2;i<=n;i++)
  a[i]=1;
for (i=2;i*i<=n;i++)
 if (a[i])
  for (j=i;j<=n/i;j++)
     a[i*j]=0;
for (i=2;i<=n;i++)
  if (a[i]) nr++;
  g<<nr;
}