Submission #802152

#	Time	Username	Problem	Language	Result	Execution time	Memory
802152		gesgha	Radio Towers (IOI22_towers)	C++17	23 / 100	4094 ms	12000 KiB

towers

#include "towers.h"
#include <bits/stdc++.h>
 
#define fr(i, a, b) for(int i = a; i <= b; i++)
#define rf(i, a, b) for(int i = a; i >= b; i--)
#define fe(x, y) for (auto& x : y)
 
#define fi first
#define se second
#define pb push_back
 
#define all(x) x.begin(), x.end()
#define pw(x) (1LL << (x))
#define sz(x) (int)x.size()
 
using namespace std;
 
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
#define fbo find_by_order
#define ook order_of_key
template <typename T>
using oset = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
 
template <typename T>
using ve = vector <T>;
 
template <typename T>
bool umx (T& a, T b) { return a < b ? a = b, 1 : 0; }
 
template <typename T>
bool umn (T& a, T b) { return a > b ? a = b, 1 : 0; }
 
using ll = long long;
using ld = long double;
using pll = pair <ll, ll>;
using pii = pair <int, int>;
using ull = unsigned long long;
 
const int oo = 1e9;
const ll OO = 1e18;
const int N = 1e5 + 10;
const int M = 5e3 + 100;
const int mod = 1e9 + 7;
const bool TEST = 0;



int spars[N][20];
int h[N];

int get(int l, int r) {
  int sz = r - l + 1;
  return max(spars[l][__lg(sz)], spars[r - pw(__lg(sz)) + 1][__lg(sz)]);
}

void init(int N, std::vector<int> H) {
  for (int i = 0; i < N; i++) h[i] = spars[i][0] = H[i];

  for (int bt = 1; pw(bt) <= N; bt++) {
    for (int i = 0; i <= N - pw(bt); i++) {
      spars[i][bt] = max(spars[i][bt - 1], spars[i + pw(bt - 1)][bt - 1]);
    }
  }
}

int max_towers(int L, int R, int D) {
  ve <pii> V;
  for (int i = L; i <= R; i++) V.pb({h[i], i});
  sort(all(V));
  set <int> HAVE;
  for (int i = 0; i < sz(V); i++) {
    if (!sz(HAVE)) {
      HAVE.insert(V[i].se);
      continue;
    }
    auto ps = HAVE.lower_bound(V[i].se);
    bool ok = 1;
    if (ps != HAVE.begin()) {
      --ps;
      int y = *ps;
      ++ps;
      int mx = get(y, V[i].se);
      ok &= (mx - D >= V[i].fi);
    }
    if (ps != HAVE.end()) {
      int y = *ps;
      int mx = get(V[i].se, y);
      ok &= (mx - D >= V[i].fi);
    }
    if (ok) HAVE.insert(V[i].se);
  }
  return sz(HAVE);
}

• Subtask 1: 0 / 4
• Subtask 2: 11 / 11
• Subtask 3: 12 / 12
• Subtask 4: 0 / 14
• Subtask 5: 0 / 17
• Subtask 6: 0 / 19
• Subtask 7: 0 / 23