Submission #841821

#	Time	Username	Problem	Language	Result	Execution time	Memory
841821		WLZ	Global Warming (CEOI18_glo)	C++17	100 / 100	749 ms	51028 KiB

glo

#include <bits/stdc++.h>
using namespace std;

const int INF = 0x3f3f3f3f;

struct node {
  int l, r, val;
  node *left, *right;
} *root0, *root1;

node *build(int l, int r) {
  if (l == r) return new node{l, r, -INF, nullptr, nullptr};
  node *left = build(l, (l + r) / 2), *right = build((l + r) / 2 + 1, r);
  return new node{l, r, -INF, left, right};
}

int query(node *cur, int l, int r) {
  if (cur->l > r || cur->r < l) return -INF;
  if (l <= cur->l && cur->r <= r) return cur->val;
  return max(query(cur->left, l, r), query(cur->right, l, r));
}

void update(node *cur, int idx, int v) {
  if (cur->l == cur->r) {
    cur->val = max(cur->val, v);
    return;
  }
  if (idx <= cur->left->r) update(cur->left, idx, v);
  else update(cur->right, idx, v);
  cur->val = max(cur->left->val, cur->right->val);
}

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n, x; cin >> n >> x;
  vector<int> a(n), b(n);
  map<int, int> mp = {{-INF, 0}};
  for (int i = 0; i < n; i++) cin >> a[i], mp[a[i]] = 0;
  int cnt = 0;
  for (auto &p : mp) p.second = cnt++;
  for (int i = 0; i < n; i++) b[i] = mp[a[i]];
  root0 = build(0, cnt - 1), root1 = build(0, cnt - 1);
  update(root0, 0, 0);
  for (int i = 0; i < n; i++) {
    update(root1, b[i], max(query(root0, 0, prev(mp.lower_bound(a[i] + x))->second), query(root1, 0, b[i] - 1)) + 1);
    update(root0, b[i], query(root0, 0, b[i] - 1) + 1);
  }
  cout << max(query(root0, 0, cnt - 1), query(root1, 0, cnt - 1)) << '\n';
  return 0;
}

• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 13 / 13
• Subtask 4: 10 / 10
• Subtask 5: 20 / 20
• Subtask 6: 17 / 17
• Subtask 7: 25 / 25