Cod sursa(job #1564943)

Utilizator c0mradec0mrade c0mrade Data 10 ianuarie 2016 01:43:04
Problema Ciurul lui Eratosthenes Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.31 kb
Raporteaza aceasta sursa 
#include<fstream>
using namespace std;
ifstream in("ciur.in");
ofstream out("ciur.out");

int n,cnt,i,j;
char x[2000000];

int main(){
    in>>n;
    for(i=2;i<=n;++i)
        if(!x[i]){
            ++cnt;
            for(j=2*i;j<=n;j+=i)
                x[j]=1;
        }
    out<<cnt;
    return 0;
}