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  1. #include <bits/stdc++.h>
  2. using namespace std;
  3.  
  4. #define FOR(i, a, b) for (auto i = (a); i <= (b); ++i)
  5. #define ROF(i, a, b) for (auto i = (a); i >= (b); --i)
  6. #define sz(x) (int)(x).size()
  7. #define pb push_back
  8. #define ppb pop_back
  9. #define endl '\n'
  10. #define fi first
  11. #define se second
  12.  
  13. #ifdef Juhan404
  14. #include "debug.h"
  15. #else
  16. #define debug(...)
  17. #endif
  18.  
  19. using ll = long long;
  20. using pii = pair<int, int>;
  21.  
  22. const int MOD = 1e9 + 7;
  23. const int N = 1e5 + 5;
  24.  
  25. int n, k, a[50];
  26. vector<string> v;
  27.  
  28. void back_tracking(string s, int cnt) {
  29.     if (sz(s) == n) {
  30.         if (cnt == k)
  31.             v.pb(s);
  32.         return;
  33.     }
  34.     back_tracking(s + '0', cnt);
  35.     back_tracking(s + '1', cnt + 1);
  36. }
  37.  
  38. void run_case() {
  39.     cin >> n >> k;
  40.     FOR(i, 1, n) {
  41.         cin >> a[i];
  42.     }
  43.     sort(a + 1, a + n + 1, greater<int>());
  44.  
  45.     back_tracking("", 0);
  46.  
  47.     for (string s : v) {
  48.         ROF(i, n - 1, 0) {
  49.             if (s[i] == '1')
  50.                 cout << a[i + 1] << " ";
  51.         }
  52.         cout << endl;
  53.     }
  54. }
  55.  
  56. int main() {
  57.     cin.tie(0)->sync_with_stdio(0);
  58.  
  59. #ifdef Juhan404
  60.     freopen("Error.txt", "w", stderr);
  61. #endif
  62.  
  63.     int T = 1;
  64.  
  65.     for (int test = 1; test <= T; ++test) {
  66.  
  67.         run_case();
  68.     }
  69.     return 0;
  70. }
Success #stdin #stdout 0.01s 5280KB
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language:

						
C++14 (gcc 8.3)

					

					

						
created:
								
						
30 days ago

					

					

						
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