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  1. #include<bits/stdc++.h>
  2. using namespace std;
  3. #define all(a) a.begin(),a.end()
  4. #define allr(a) a.rbegin(),a.rend()
  5. #define ll long long
  6. const ll mod = 1000000007;
  7.  
  8. int lset(int n){
  9.     int cnt = 0;
  10.     for(int i = 0; i < 32; i++){
  11.         if(n&(1<<i)) cnt = i;
  12.     }
  13.     return cnt+1;
  14. }
  15.  
  16. int fun(vector<int>&v){
  17.     int k = 0;
  18.     for(int i = 0; i < v.size(); i++){
  19.         if((i+1) & 1) k = k&v[i];
  20.         else k = k|v[i];
  21.     }
  22.     return k; 
  23. }
  24. void solve()
  25. {
  26.     int n;cin>>n;
  27.     vector<int> v;
  28.  
  29.     if(n%2 == 0){
  30.         cout << (1<<lset(n))-1  << endl; 
  31.         int ele = (1<<(lset(n)-1))-1;
  32.         for(int i = 1; i <= n; i++) if(i != ele) v.push_back(i);
  33.         v.push_back(ele);
  34.     } else {
  35.         cout << n << endl;
  36.         int a = 1,b = 3;
  37.         for(int i = 1; i < n-1; i++){
  38.             if(i != a && i != b) v.push_back(i);
  39.         }
  40.         v.push_back(a),v.push_back(b),v.push_back(n-1),v.push_back(n);
  41.     }
  42.  
  43.     // 10111
  44.     // 10110
  45.  
  46.     cout << fun(v) << endl;
  47.     for(auto it:v) cout << it << " ";
  48.     cout << endl;
  49. }
  50.  
  51. int main()
  52. {
  53.     ios::sync_with_stdio(false);
  54.     cin.tie(0);
  55.  
  56.     int t = 1;
  57.     cin>>t;
  58.     while(t--){
  59.         solve();
  60.     }
  61.     return 0;
  62. }
Success #stdin #stdout 0.01s 5280KB
comments ()
stdin 
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stdout 
23
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https://ideone.com/o5eTZD
language:
C++14 (gcc 8.3)
created:
4 days ago
visibility:
public

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