Cod sursa(job #2912571)
Utilizator | Data | 9 iulie 2022 11:58:45 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva educationala | Marime | 0.49 kb |
#include <bits/stdc++.h>
using namespace std;
ifstream fin("ciur.in");
ofstream fout("ciur.out");
int main()
{
int n, contor = 1;
fin >> n;
vector < bool > isPrime(n + 1, true);
for(int i = 3; i <= n; i += 2)
{
if(isPrime[i] == true)
{
contor++;
for(int j = i * 3; j <= n; j += i * 2)
{
isPrime[j] = false;
}
}
}
fout << contor;
return 0;
}