Cod sursa(job #2016065)

Utilizator mariusbsUnibuc Serban mariusbs Data 28 august 2017 15:16:32
Problema Ciurul lui Eratosthenes Scor 30
Compilator cpp Status done
Runda Arhiva educationala Marime 0.34 kb
Raporteaza aceasta sursa 
#include<iostream>
#include<fstream>
using namespace std;
ifstream in("ciur.in");
ofstream out("ciur.out");

bool v[2000001];
 
int main(){
 
unsigned int n,i,d,cnt=0;
in>>n;
if(n>=2)
    cnt++;
for(i=3;i<=n;i+=2)
    if(v[i]==0){
        cnt++;
        for(d=i*i;d<=n;d+=i)
            v[d]=1;
    }
out<<cnt;

 
return 0;   
}