Submission #515715

#	Time	Username	Problem	Language	Result	Execution time	Memory
515715		MilosMilutinovic	Global Warming (CEOI18_glo)	C++14	38 / 100	2071 ms	6288 KiB

glo

#include <bits/stdc++.h>

using namespace std;

template <typename T>
class fenwick {
  public:
  vector<T> fenw;
  int n;
  fenwick(int _n) : n(_n) {
    fenw.resize(n);
  }
  void modify(int x, T v) {
    while (x < n) {
      fenw[x] += v;
      x |= (x + 1);
    }
  }
  T get(int x) {
    T v{};
    while (x >= 0) {
      v += fenw[x];
      x = (x & (x + 1)) - 1;
    }
    return v;
  }
};
struct node {
  int a = 0; // don't forget to set default value
  inline void operator += (node &other) {
    a = max(a, other.a);
  }
};

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n, x;
  cin >> n >> x;
  vector<int> a(n);
  for (int i = 0; i < n; i++) {
    cin >> a[i];
  }
  auto Solve = [&](vector<int> v) {
    vector<int> cs;
    for (int i = 0; i < n; i++) {
      cs.push_back(v[i]);
    }
    sort(cs.begin(), cs.end());
    cs.erase(unique(cs.begin(), cs.end()), cs.end());
    fenwick<node> fenw(n);
    vector<int> dp(n);
    for (int i = 0; i < n; i++) {
      v[i] = lower_bound(cs.begin(), cs.end(), v[i]) - cs.begin();
      dp[i] = fenw.get(v[i] - 1).a + 1;
      fenw.modify(v[i], {dp[i]});
    }
    return *max_element(dp.begin(), dp.end());
  };
  int ans = Solve(a);
  if (x == 0) {
    cout << ans << '\n'; // lol
    return 0;
  }
  for (int i = 0; i < n; i++) {
    a[n - i - 1] += x;
    ans = max(ans, Solve(a));
  }
  for (int i = 0; i < n; i++) {
    a[i] -= x;
    ans = max(ans, Solve(a));
  }
  cout << ans << '\n';
  return 0;
}

• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 13 / 13
• Subtask 4: 10 / 10
• Subtask 5: 0 / 20
• Subtask 6: 0 / 17
• Subtask 7: 0 / 25