Cod sursa(job #2630895)
Utilizator | Radu Andrei valkir69 | Data | 27 iunie 2020 19:54:53 |
---|---|---|---|
Problema | Suma si numarul divizorilor | Scor | 0 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva educationala | Marime | 0.54 kb |
#include <iostream>
#include <fstream>
#include <cmath>
using namespace std;
ifstream fin("ciur.in");
ofstream fout("ciur.out");
const int NMAX = 2000005;
bool A[NMAX];
int n, cnt;
int main() {
fin >> n;
for(int i = 2; i <= n; ++i) A[i] = true;
for(int i = 2; i <= n; ++i){
if(A[i] == true){
++cnt;
for(int j = i+i; j <= n; j+=i){
A[j] = false;
}
}
}
fout << cnt;
fout.close();
fin.close();
return 0;
}