Cod sursa(job #3220484)
Utilizator | Data | 3 aprilie 2024 19:44:56 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 70 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva educationala | Marime | 0.34 kb |
#include <fstream>
using namespace std;
ifstream cin("ciur.in");
ofstream cout("ciur.out");
int a[2000001];
int main()
{
int n;
cin>>n;
int c=0;
for(int i=2;i<=n;i++){
if(a[i]==0){
c++;
for(int j=i+i;j<=n;j+=i){
a[j]=1;
}}
}
cout<<c;
return 0;
}