Submission #825002

#	Time	Username	Problem	Language	Result	Execution time	Memory
825002		LittleCube	Radio Towers (IOI22_towers)	C++17	23 / 100	4069 ms	3492 KiB

towers

#include "towers.h"
#include <bits/stdc++.h>
#define ll long long
#define pii pair<int, int>
#define pll pair<ll, ll>
#define F first
#define S second
using namespace std;

namespace
{
  int N;
  vector<int> H, p, l, r, vis;
}

void init(int _N, vector<int> _H)
{
  H = _H;
}

int max_towers(int L, int R, int D)
{
  H = vector<int>(H.begin() + L, H.begin() + R + 1);
  N = (int)H.size();
  H.emplace_back(2e9);

  p = vector<int>(N + 1, 0);
  vis = vector<int>(N + 1, 0);
  l = r = p;
  vector<int> mono = {N};
  
  for (int i = 0; i <= N; i++)
  {
    while (H[mono.back()] < H[i])
      r[mono.back()] = i, mono.pop_back();
    l[i] = mono.back();
    mono.push_back(i);
  }

  for (int i = 0; i < N; i++)
    if (H[l[i]] < H[r[i]])
      p[i] = l[i];
    else
      p[i] = r[i];

  vector<int> v;
  for (int i = 0; i < N; i++)
    vis[p[i]] = 1;
  for (int i = 0; i < N; i++)
    if (!vis[i])
      v.emplace_back(i);
  sort(v.begin(), v.end(), [&](int i, int j)
       { return H[i] < H[j]; });

  for (int i = 0; i < N; i++)
    vis[i] = 0;
  int ans = 0;
  for (auto i : v)
    if (!vis[i])
    {
      int c = i;
      bool flag = 1;
      while (c != N)
      {
        if (H[c] < H[i] + D && vis[c])
          flag = 0;
        vis[c] = 1;
        c = p[c];
      }
      if (flag)
        ans++;
    }
  return ans;
}

• 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