fork(1) download
copy 
  1. #include <bits/stdc++.h>
  2. using namespace std;
  3.  
  4. // Speed
  5. #define fast_io ios::sync_with_stdio(0); cin.tie(0); cout.tie(0)
  6.  
  7. // Typedefs
  8. #define int long long
  9. #define pb push_back
  10. #define ff first
  11. #define ss second
  12. #define all(x) (x).begin(), (x).end()
  13. #define rall(x) (x).rbegin(), (x).rend()
  14. #define sz(x) ((int)(x).size())
  15. #define endl '\n'
  16. #define yes cout << "yes\n"
  17. #define no cout << "no\n"
  18.  
  19. // Loops
  20. #define rep(i,a,b) for(int i=a;i<b;++i)
  21. #define per(i,a,b) for(int i=b-1;i>=a;--i)
  22. #define each(x, a) for (auto& x : a)
  23.  
  24. // Consts
  25. const int INF = 1e18;
  26. const int MOD = 1e9+7;
  27. const int N = 2e5 + 5;
  28.  
  29. // Math
  30. int gcd(int a, int b) { return b == 0 ? a : gcd(b, a % b); }
  31. int lcm(int a, int b) { return (a / gcd(a, b)) * b; }
  32.  
  33. int power(int a, int b, int m = MOD) {
  34.     int res = 1;
  35.     while (b > 0) {
  36.         if (b & 1) res = res * a % m;
  37.         a = a * a % m;
  38.         b >>= 1;
  39.     }
  40.     return res;
  41. }
  42.  
  43. int modinv(int a, int m = MOD) {
  44.     return power(a, m - 2, m);
  45. }
  46.  
  47. // Logic
  48. void solve() {
  49.     int n;
  50.     cin >> n;
  51.     int N = 1 << n;
  52.     vector<int> ans;
  53.     vector<int> used(N, 0);
  54.  
  55.     for (int bit = n - 1; bit >= 0; bit--) {
  56.         for (int x = 0; x < N; x++) {
  57.             if (!used[x] && x && ((x >> bit) & 1) && (31 - __builtin_clz(x) == bit)) {
  58.                 ans.push_back(x);
  59.                 used[x] = 1;
  60.             }
  61.         }
  62.     }
  63.  
  64.     if (!used[0]) ans.push_back(0);
  65.  
  66.     for (int x : ans) cout << x << " ";
  67.     cout << '\n';
  68. }
  69.  
  70.  
  71.  
  72. // Main
  73. int32_t main() {
  74.     fast_io;
  75.  
  76.     int t;
  77.     cin >> t;
  78.     while (t--) {
  79.         solve();
  80.     }
  81.  
  82.     return 0;
  83. }
  84.  
Success #stdin #stdout 0.01s 5312KB
comments (?)
stdin
copy 
2
1
2
stdout
copy 
1 0 
2 3 1 0
https://ideone.com/bUhw07
language:
C++ (gcc 8.3)
created:
1 day ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!