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  1. #include <bits/stdc++.h> // NeOWami
  2. using namespace std;
  3.  
  4. #define ft first
  5. #define sc second
  6. #define int long long
  7. using pii = pair<int, int>;
  8. template<class T> using heapmin = priority_queue<T, vector<T>, greater<T>>;
  9.  
  10. const int N = 3e5 + 5;
  11.  
  12. int n, k;
  13. int a[N];
  14. int val[N], L[N], R[N], curID;
  15. bool del[N];
  16. signed main() {
  17.     cin.tie(NULL)->sync_with_stdio(false);
  18.     if(ifstream("BACKUP.inp")) {
  19.         freopen("BACKUP.inp", "r", stdin);
  20.         freopen("BACKUP.out", "w", stdout);
  21.     }
  22.     cin >> n >> k;
  23.     for (int i = 1; i <= n; i++) cin >> a[i];
  24.     sort(a + 1, a + n + 1);
  25.     heapmin<pii> pq;
  26.     for (int i = 1; i < n; i++) {
  27.         ++curID;
  28.         val[i] = a[i + 1] - a[i];
  29.         L[i] = i - 1;
  30.         R[i] = (i + 1 == n) ? 0 : i + 1;
  31.         pq.push({val[i], i});
  32.     }
  33.  
  34.     curID = n;
  35.     int cnt = 0, ans = 0;
  36.     while(cnt < k) {
  37.         int i = pq.top().sc;
  38.         pq.pop();
  39.         if (del[i]) continue; 
  40.         ans += val[i];
  41.         del[i] = 1;
  42.         cnt++;
  43.  
  44.         int l = L[i], r = R[i];
  45.         del[l] = del[r] = 1;
  46.  
  47.         int leftL = l ? L[l] : 0; 
  48.         int rightR = r ? R[r] : 0; 
  49.         if (l && r) {
  50.             int id = ++curID;
  51.             val[id] = val[l] + val[r] - val[i];
  52.             L[id] = leftL, R[id] = rightR;
  53.             if (leftL) R[leftL] = id;
  54.             if (rightR) L[rightR] = id;
  55.             del[id] = 0;
  56.             pq.push({val[id], id});
  57.         }
  58.         else {
  59.             if (leftL) R[leftL] = rightR;
  60.             if (rightR) L[rightR] = leftL;
  61.         }
  62.     }
  63.     cout << ans;
  64.     return 0;
  65. }
Success #stdin #stdout 0.01s 5280KB
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stdout 
Standard output is empty
https://ideone.com/l9YwdZ
language:
C++14 (gcc 8.3)
created:
12 days ago
visibility:
public

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