oj.uz

Submission #958904

# Submission time Handle Problem Language Result Execution time Memory
958904 2024-04-07T03:31:14 Z ad_red Watching (JOI13_watching) C++17
50 / 100
 1000 ms 12396 KB 
#include <bits/stdc++.h>
#define endl "\n"

#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")

using namespace std;
using ll = long long;

ll inf = 5 * 1e9;

void pv(vector<vector<ll>> s) {
  for (auto c : s) {
    for (auto q : c) {
      cout << q << " ";
    }
    cout << endl;
  }
}

bool check(vector<ll>& s, ll w, ll p, ll q) {
  vector<vector<ll>> dp((int)s.size() + 1, vector<ll>(p + 1, 0));

  // храним что?
  // минимальное число использованных больших камер
  // dp[i][j] - мин.число бол.камер, которыми можно покрыть все события до i-го при условии, что остается еще j маленьких камер

  // dp[i][j - 1] = dp[k][j], где k находим бинпоиском по размеру большой камеры
  // dp[i][j] = dp[k][j] + 1, где k находим бинпоиском по размеру маленькой камеры

  for (int i = 0; i < s.size(); i++) {
    bool flag = false;
    for (int j = 0; j <= p; j++) {
      ll l = 0, r = i + 1;
      while (r - l > 1) {
        ll mid = (r + l) / 2;
        if (s[i - mid] + w > s[i]) {
          l = mid;
        } else {
          r = mid;
        }
      }
      ll ind_small = i - l;

      l = 0;
      r = i + 1;
      while (r - l > 1) {
        ll mid = (r + l) / 2;
        if (s[i - mid] + 2 * w > s[i]) {
          l = mid;
        } else {
          r = mid;
        }
      }
      ll ind_big = i - l;

      dp[i + 1][j] = inf;
      if (j > 0) dp[i + 1][j] = min(dp[i + 1][j], dp[ind_small][j - 1]);
      dp[i + 1][j] = min(dp[i + 1][j], dp[ind_big][j] + 1);

      if (dp[i + 1][j] <= q) flag = true;
    }
    if (!flag) return false;
  }

  // pv(dp);
  // cout << endl;

  return true;
}

int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);

  ll n, p, q;
  cin >> n >> p >> q;

  vector<ll> s(n);


  for (int i = 0; i < n; i++) {
    cin >> s[i];
  }

  if (p + q >= n) {
    cout << "1" << endl;
    return 0;
  }

  sort(s.begin(), s.end());

  ll l = 0;
  ll r = inf;

  while (r - l > 1) {
    ll mid = (r + l) / 2;
    if (check(s, mid, p, q)) {
      r = mid;
    } else {
      l = mid;
    }
  }

  cout << r << endl;

  return 0;
}

Compilation message

watching.cpp: In function 'bool check(std::vector<long long int>&, ll, ll, ll)':
watching.cpp:31:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   31 |   for (int i = 0; i < s.size(); i++) {
      |                   ~~^~~~~~~~~~

Subtask #1
50.0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 348 KB Output is correct
2 Correct 1 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 1 ms 348 KB Output is correct
6 Correct 1 ms 348 KB Output is correct
7 Correct 1 ms 348 KB Output is correct
8 Correct 1 ms 344 KB Output is correct
9 Correct 2 ms 348 KB Output is correct
10 Correct 2 ms 348 KB Output is correct
11 Correct 5 ms 344 KB Output is correct
12 Correct 4 ms 348 KB Output is correct
13 Correct 1 ms 348 KB Output is correct
14 Correct 1 ms 348 KB Output is correct
15 Correct 1 ms 348 KB Output is correct

Subtask #2
0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 9 ms 348 KB Output is correct
2 Correct 1 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 1 ms 348 KB Output is correct
5 Correct 0 ms 348 KB Output is correct
6 Correct 1 ms 348 KB Output is correct
7 Correct 53 ms 604 KB Output is correct
8 Correct 424 ms 2660 KB Output is correct
9 Execution timed out 1059 ms 12396 KB Time limit exceeded
10 Halted 0 ms 0 KB -