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  1. #include<bits/stdc++.h>
  2. using namespace std;
  3.  
  4. using ll = long long;
  5.  
  6. template<typename X, typename Y>
  7. bool chmax(X& a, Y b) { return (a < b) ? a = b, 1 : 0; }
  8.  
  9. template<typename X, typename Y>
  10. bool chmin(X& a, Y b) { return (a > b) ? a = b, 1 : 0; }
  11.  
  12. const int N = 2e5+5;
  13.  
  14. int n, q, a[N];
  15.  
  16. struct Node {
  17.     int lc, rc, cnt;
  18. } st[22*N];
  19.  
  20. int roots[N], nodes = 0;
  21.  
  22. int update(int p, int l, int r, int k) {
  23.     int id = ++nodes;
  24.     st[id] = st[p];
  25.     st[id].cnt++;
  26.     if (l == r) return id;
  27.     int mid = (l + r) >> 1;
  28.     if (k <= mid) st[id].lc = update(st[p].lc, l, mid, k);
  29.     else st[id].rc = update(st[p].rc, mid + 1, r, k);
  30.     return id;
  31. }
  32.  
  33. int query(int L, int R, int l, int r, int k) {
  34.     if (l == r) return l;
  35.     int cnt = st[st[R].lc].cnt - st[st[L].lc].cnt;
  36.     int mid = (l + r) >> 1;
  37.     if (cnt >= k) return query(st[L].lc, st[R].lc, l, mid, k);
  38.     return query(st[L].rc, st[R].rc, mid + 1, r, k - cnt);
  39. }
  40.  
  41. void solve() {
  42.     cin >> n >> q;
  43.     vector<int> vals;
  44.     for (int i = 1; i <= n; i++) {
  45.         cin >> a[i];
  46.         vals.push_back(a[i]);
  47.     }
  48.     sort(vals.begin(), vals.end());
  49.     vals.erase(unique(vals.begin(), vals.end()), vals.end());
  50.     int m = vals.size();
  51.     for (int i = 1; i <= n; i++) {
  52.         a[i] = lower_bound(vals.begin(), vals.end(), a[i]) - vals.begin() + 1;
  53.         roots[i] = update(roots[i - 1], 1, m, a[i]);
  54.     }
  55.     while (q--) {
  56.         int l, r, k; cin >> l >> r >> k;
  57.         int p = query(roots[l - 1], roots[r], 1, m, k);
  58.         cout << vals[p - 1] << '\n';
  59.     }    
  60. }
  61.  
  62. int main() {
  63.     ios_base::sync_with_stdio(false); cin.tie(NULL);
  64.  
  65.     int tests = 1; // cin >> tests;
  66.     while (tests--) solve();
  67.  
  68.     #ifdef LOCAL
  69.     cerr << "\nTime elapsed: " << clock() << ' ms.\n';
  70.     #endif
  71.     return 0;
  72. }
Success #stdin #stdout 0.01s 5284KB
comments (?)
stdin
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7 3
1 5 2 6 3 7 4
2 5 3
4 4 1
1 7 3
stdout
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5
6
3
https://ideone.com/mfucZV
language:
C++14 (gcc 8.3)
created:
1 day ago
visibility:
public

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