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  1. #include <bits/stdc++.h>
  2. using namespace std;
  3. #define int              long long int
  4. #define double           long double
  5. #define print(a)         for(auto x : a) cout << x << " "; cout << endl
  6. inline int power(int a, int b) {
  7.     int x = 1;
  8.     while (b) {
  9.         if (b & 1) x *= a;
  10.         a *= a;
  11.         b >>= 1;
  12.     }
  13.     return x;
  14. }
  15.  
  16.  
  17. const int M = 1000000007;
  18. const int N = 3e5+9;
  19. const int INF = 2e9+1;
  20. const int LINF = 2000000000000000001;
  21.  
  22. //_ ***************************** START Below *******************************
  23.  
  24. vector<int> a;
  25. vector<int> generateOrder(int n, int valleys){
  26. 	int s = 0, e = n-1;
  27. 	vector<int> order(n);
  28.  
  29. 	int j = 0;
  30. 	for(int i=1; i<n; i+=2){
  31. 		order[i] = a[j];
  32. 		j++;
  33. 	}
  34. 	for(int i=0; i<n; i+=2){
  35. 		order[i] = a[j];
  36. 		j++;
  37. 	}
  38.  
  39. 	return order;
  40. }
  41.  
  42. bool isPossible(int n, int mid){
  43. 	vector<int> valleys(n);
  44.  
  45. 	int j = 0;
  46. 	for(int i=1; i<n; i+=2){
  47. 		valleys[i] = a[j];
  48. 		j++;
  49. 	}
  50. 	for(int i=0; i<n; i+=2){
  51. 		valleys[i] = a[j];
  52. 		j++;
  53. 	}
  54.  
  55. 	int ct = 0;
  56. 	for(int i=1; i<n-1; i+=2){
  57. 		if(valleys[i] < valleys[i-1] && valleys[i] < valleys[i+1]) ct++;
  58. 	}
  59.  
  60. 	return ct >= mid;
  61. }
  62.  
  63. pair<int, vector<int>> consistency1(int n){
  64.  
  65. 	sort(begin(a), end(a));
  66.  
  67. 	int s = 0, e = n;
  68. 	while(s<e){
  69. 		int mid = s + (e-s+1)/2;
  70. 		if(isPossible(n, mid)){
  71. 			s = mid;
  72. 		}
  73. 		else e = mid-1;
  74. 	}
  75.  
  76. 	return {e, generateOrder(n, e) };
  77.  
  78. }
  79.  
  80.  
  81.  
  82.  
  83.  
  84.  
  85. pair<int, vector<int>> consistency2(int n){
  86.  
  87. 	sort(begin(a), end(a));
  88. 	vector<int> order(n);
  89.  
  90. 	int j = 0;
  91. 	for(int i=1; i<n; i+=2){
  92. 		order[i] = a[j];
  93. 		j++;
  94. 	}
  95. 	for(int i=0; i<n; i+=2){
  96. 		order[i] = a[j];
  97. 		j++;
  98. 	}
  99.  
  100. 	int ct = 0;
  101. 	for(int i=1; i<n-1; i+=2){
  102. 		if(order[i] < order[i-1] && order[i] < order[i+1]) ct++;
  103. 	}
  104.  
  105.  
  106. 	return {ct, order };
  107.  
  108. }
  109.  
  110.  
  111.  
  112.  
  113.  
  114.  
  115.  
  116.  
  117.  
  118.  
  119. void solve() {
  120.  
  121.     int n;
  122.     cin>>n;
  123.  
  124.     a.resize(n);
  125.     for(int i=0; i<n; i++) cin >> a[i];
  126.  
  127.     auto ans1 = consistency1(n);
  128.  
  129.     cout << ans1.first << endl;
  130.     for(auto& it : ans1.second){
  131.         cout << it << " ";
  132.     }cout << endl;
  133.  
  134.  
  135.  
  136.     // cout << " : " << endl;
  137.  
  138.  
  139.     // auto ans2 = consistency2(n);
  140.  
  141.     // cout << ans2.first << endl;
  142.     // for(auto& it : ans2.second){
  143.     //     cout << it << " ";
  144.     // }cout << endl;
  145.  
  146.  
  147. }
  148.  
  149.  
  150.  
  151.  
  152.  
  153. int32_t main() {
  154.     ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
  155.  
  156.     int t = 1;
  157.     // cin >> t;
  158.     while (t--) {
  159.         solve();
  160.     }
  161.  
  162.     return 0;
  163. }
Success #stdin #stdout 0s 5308KB
comments (?)
stdin
copy 
5
1 2 2 4 5
7
1 3 2 2 4 5 4
6
4 1 4 4 4 4 
6
4 1 2 3 2 4
stdout
copy 
2
2 1 4 2 5 
 : 
2
2 1 4 2 5
https://ideone.com/OiaXT4
language:
C++14 (gcc 8.3)
created:
1 hour ago
visibility:
public

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