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  1. #include <iostream>
  2. #include <vector>
  3.  
  4. using namespace std;
  5.  
  6. int main() {
  7.     ios_base::sync_with_stdio(false);
  8.     cin.tie(NULL);
  9.  
  10.     int n;
  11.     if (!(cin >> n)) return 0;
  12.  
  13.     if (n < 2) return 0;
  14.  
  15.     vector<bool> is_prime(n + 1, true);
  16.     is_prime[0] = is_prime[1] = false;
  17.  
  18.     for (int p = 2; p * p <= n; p++) {
  19.         if (is_prime[p]) {
  20.             for (int i = p * p; i <= n; i += p)
  21.                 is_prime[i] = false;
  22.         }
  23.     }
  24.  
  25.     for (int p = 2; p <= n; p++) {
  26.         if (is_prime[p]) {
  27.             cout << p << " ";
  28.         }
  29.     }
  30.  
  31.     return 0;
  32. }
Success #stdin #stdout 0s 5296KB
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https://ideone.com/XXdEBh
language:
C++ (gcc 8.3)
created:
2 days ago
visibility:
public

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