Cod sursa(job #2255606)

Utilizator lucianistratiIstrati Lucian lucianistrati Data 7 octombrie 2018 12:14:38
Problema Ciurul lui Eratosthenes Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 0.42 kb
#include <iostream>
#include <fstream>
#include <math.h>
using namespace std;
int a[2000001];
int main()
{
    ifstream fin("ciur.in");
    ofstream fout("ciur.out");
    int N,i,j,t=0;
    fin>>N;
    for(i=2;i<=sqrt(N);++i)
    {
        if(a[i]==0)
        t++;
        for(j=i*i;j<=N;j=j+i)
        {
            a[j]=1;
        }
    }
    fout<<t;
    fin.close();
    fout.close();
    return 0;
}