Cod sursa(job #2563526)

Utilizator kerry6205Motiu Radu kerry6205 Data 1 martie 2020 12:17:24
Problema Ciurul lui Eratosthenes Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.34 kb
Raporteaza aceasta sursa 
#include <iostream>
#include <fstream>
using namespace std;
bool a[2000010];

ifstream fin("ciur.in");
ofstream fout("ciur.out");

int main()
{
    int N,i,j,c=0;
    fin>>N;
    for(i=2;i<=N;i++)
        if(!a[i])
        {
            c++;
            for(j=i+i;j<=N;j+=i)
                a[j]=1;
        }
    fout<<c;
}