Submission #782987

#	Time	Username	Problem	Language	Result	Execution time	Memory
782987		tvladm2009	Triple Jump (JOI19_jumps)	C++17	27 / 100	35 ms	21000 KiB

jumps

#include <bits/stdc++.h>

using namespace std;
const int N = (int) 5e5 + 7;
const int INF = (int) 2e9;
int n, a[N], nextBigger[N], q;

struct rmq {
  const int K = 20;
  vector<vector<int>> tab;
  vector<int> lg2;
  int n;

  void init(int nn) {
    n = nn;
    lg2.resize(n + 1);
    for (int i = 2; i <= n; i++) {
      lg2[i] = 1 + lg2[i / 2];
    }
    tab.resize(K);
    for (int i = 0; i < K; i++) {
      tab[i].resize(n + 1);
    }
  }

  void build(int a[]) {
    for (int i = 1; i <= n; i++) {
      tab[0][i] = a[i];
    }
    for (int k = 1; k < K; k++) {
      for (int i = 1; i + (1 << k) - 1 <= n; i++) {
        tab[k][i] = max(tab[k - 1][i], tab[k - 1][i + (1 << (k - 1))]);
      }
    }
  }

  int query(int x, int y) {
    if (x > y) {
      return -INF;
    }
    assert(1 <= x && x <= y && y <= n);
    int p = lg2[y - x + 1];
    return max(tab[p][x], tab[p][y - (1 << p) + 1]);
  }
};

signed main() {
  ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);

  ///freopen("input", "r", stdin);

  cin >> n;
  for (int i = 1; i <= n; i++) {
    cin >> a[i];
  }
  rmq rmq;
  rmq.init(n);
  rmq.build(a);
  if (n <= 5000) {
    vector<vector<int>> mx(n + 1, vector<int>(n + 1));
    for (int l = 1; l <= n; l++) {
      for (int r = l + 2; r <= n; r++) {
        mx[l][r] = a[l] + a[r] + rmq.query(l + 1, (l + r) / 2);
      }
    }
    for (int l = 1; l <= n; l++) {
      for (int r = l + 2; r <= n; r++) {
        mx[l][r] = max(mx[l][r], mx[l][r - 1]);
        mx[l][r] = max(mx[l][r], mx[l + 1][r]);
      }
    }
    cin >> q;
    while (q--) {
      int l, r;
      cin >> l >> r;
      cout << mx[l][r] << "\n";
    }
    return 0;
  }

  {
    vector<int> st;
    for (int i = n; i >= 1; i--) {
      while (!st.empty() && a[i] >= a[st.back()]) {
        st.pop_back();
      }
      if (st.empty()) {
        nextBigger[i] = n + 1;
      } else {
        nextBigger[i] = st.back();
      }
      st.push_back(i);
    }
  }
  cin >> q;
  for (int iq = 1; iq <= q; iq++) {
    int l, r, best = 0;
    cin >> l >> r;
    for (int i = l; i <= r; i++) {
      for (int j = i + 1; j <= min(n, nextBigger[i]); j = nextBigger[j]) {
        best = max(best, a[i] + a[j] + rmq.query(2 * j - i, r));
      }
    }
    cout << best << "\n";
  }
  return 0;
}

• Subtask 1: 0 / 5
• Subtask 2: 0 / 14
• Subtask 3: 27 / 27
• Subtask 4: 0 / 54