Submission #1292294

#	Time	Username	Problem	Language	Result	Execution time	Memory
1292294		lmquan	Road Construction (JOI21_road_construction)	C++20	100 / 100	1538 ms	10380 KiB

road_construction

#define taskname ""
#include <bits/stdc++.h>
using namespace std;
const long long kMaxDist = 4000000000;
const long long kInf = 5000000000000000000;

int main() {
  if (fopen(taskname".inp", "r")) {
    freopen(taskname".inp", "r", stdin);
    freopen(taskname".out", "w", stdout);
  }
  ios_base::sync_with_stdio(false);
  cin.tie(nullptr);

  int n, k;
  cin >> n >> k;
  vector<pair<long long, long long>> a(n + 1);
  for (int i = 1; i <= n; i++) {
    cin >> a[i].first >> a[i].second;
    a[i] = {a[i].first + a[i].second, a[i].first - a[i].second};
  }
  sort(a.begin() + 1, a.end());

  auto f = [&](long long d) -> pair<long long, vector<long long>> {
    set<pair<long long, long>> s;
    queue<pair<long long, long long>> q;
    vector<long long> v;
    int c = 0;
    for (int i = 1; i <= n; i++) {
      while (!q.empty() && q.front().first < a[i].first - d) {
        s.erase({q.front().second, q.front().first});
        q.pop();
      }
      auto it = s.lower_bound({a[i].second - d, -kInf});
      while (it != s.end() && it->first <= a[i].second + d) {
        c++;
        v.push_back(max(abs(a[i].second - it->first), a[i].first - it->second));
        if (c >= k) {
          break;
        }
        it++;
      }
      if (c >= k) {
        break;
      }
      s.insert({a[i].second, a[i].first});
      q.push({a[i].first, a[i].second});
    }
    return {c, v};
  };

  long long low = 1, high = kMaxDist, x;
  while (low <= high) {
    long long mid = (low + high) / 2;
    pair<long long, vector<long long>> b = f(mid);
    if (b.first >= k) {
      x = mid;
      high = mid - 1;
    } else {
      low = mid + 1;
    }
  }

  vector<long long> e = f(x - 1).second;
  sort(e.begin(), e.end());
  for (auto i : e) {
    cout << i << '\n';
  }
  for (int i = 1; i <= k - e.size(); i++) {
    cout << x << '\n';
  }

  return 0;
}

Compilation message (stderr)

road_construction.cpp: In function 'int main()':
road_construction.cpp:9:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    9 |     freopen(taskname".inp", "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~
road_construction.cpp:10:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   10 |     freopen(taskname".out", "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 6 / 6
• Subtask 3: 7 / 7
• Subtask 4: 20 / 20
• Subtask 5: 27 / 27
• Subtask 6: 35 / 35