Submission #1081626

#	Time	Username	Problem	Language	Result	Execution time	Memory
1081626		juicy	Autobahn (COI21_autobahn)	C++17	100 / 100	186 ms	22088 KiB

autobahn

#include <bits/stdc++.h>

using namespace std;

#ifdef LOCAL
#include "debug.h"
#else
#define debug(...) 42
#endif

const int N = 1e5 + 5;

int n, k, L;
int l[N], r[N], t[N], a[9 * N], b[9 * N];
long long pf[9 * N];

void upd(int i, int j, int *a) {
  ++a[i];
  --a[j];
}

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

  cin >> n >> k >> L;
  vector<int> comp;
  for (int i = 1; i <= n; ++i) {
    cin >> l[i] >> t[i] >> r[i];
    comp.push_back(l[i]);
    comp.push_back(r[i] + 1);
    if (r[i] - l[i] + 1 <= t[i]) {
      t[i] = -1;
      continue;
    }
    comp.push_back(l[i] + t[i]);
  }
  int m = comp.size();
  for (int i = 0; i < m; ++i) {
    comp.push_back(comp[i] + L);
    comp.push_back(comp[i] - L);
  }
  sort(comp.begin(), comp.end());
  comp.erase(unique(comp.begin(), comp.end()), comp.end());
  auto pos = [&](int i) {
    return lower_bound(comp.begin(), comp.end(), i) - comp.begin() + 1;
  };
  m = comp.size();
  for (int i = 1; i <= n; ++i) {
    int x = pos(l[i]), y = pos(r[i] + 1);
    upd(x, y, a);
    if (~t[i]) {
      int z = pos(l[i] + t[i]);
      upd(z, y, b);
    }
  }
  for (int i = 1; i <= m; ++i) {
    a[i] += a[i - 1];
    b[i] += b[i - 1];
    if (i + 1 <= m) {
      pf[i + 1] = pf[i] + (long long) (comp[i] - comp[i - 1]) * (a[i] >= k ? b[i] : 0);
    }
  }
  long long res = 0;
  for (int i = 1; i <= m; ++i) {
    int y = pos(comp[i - 1] + L);
    if (y <= m && comp[y - 1] == comp[i - 1] + L) {
      res = max(res, pf[y] - pf[i]);
    }
  }
  cout << res;
  return 0;
}

• Subtask 1: 20 / 20
• Subtask 2: 30 / 30
• Subtask 3: 50 / 50