2022/round2/balance_sheet.cpp

#include <algorithm>
#include <iostream>
#include <vector>
using namespace std;

const int LIM = 1000005;
const int MOD = 1000000007;
using LL = long long;
using vll = vector<LL>;

struct event {
  int id;
  int day;
  int price;
  char type;

  bool operator<(const event &e) const {
    if (day != e.day) {
      return day > e.day;
    }
    return price > e.price;
  }
};

// Merges two lists already sorted in reverse, trimmed to K elements.
// Optionally add a constant c2 to each element of v2 in the result.
vll merge(const vll &v1, const vll &v2, int K, LL c2 = 0) {
  vll res;
  int i = 0, j = 0, sz1 = v1.size(), sz2 = v2.size();
  while (i < sz1 && j < sz2 && (int)res.size() < K) {
    if (v1[i] >= v2[j] + c2) {
      res.push_back(v1[i++]);
    } else {
      res.push_back(v2[j++] + c2);
    }
  }
  while (i < sz1 && (int)res.size() < K) {
    res.push_back(v1[i++]);
  }
  while (j < sz2 && (int)res.size() < K) {
    res.push_back(v2[j++] + c2);
  }
  return res;
}

int solve() {
  int N, K;
  cin >> N >> K;
  vector<event> E;
  for (int i = 0, a, b, x, y; i < N; i++) {
    cin >> a >> b >> x >> y;
    E.push_back({i, a, x, 'B'});
    E.push_back({i, b, y, 'S'});
  }
  sort(E.begin(), E.end());
  int prevday = -1;
  vector<vll> P(N, {0});
  vll V;
  for (const event &e : E) {
    if (prevday != e.day) {
      V.clear();
    }
    if (e.type == 'B') {
      V = merge(V, P[e.id], K, e.price);
    } else {
      vll V2;
      for (LL v : V) {
        if (v > e.price) {
          V2.push_back(v - e.price);
        }
      }
      P[e.id] = merge(P[e.id], V2, K);
    }
    prevday = e.day;
  }
  V.clear();
  for (int i = 0; i < N; i++) {
    V = merge(V, P[i], K);
  }
  LL res = 0;
  for (LL v : V) {
    res = (res + v) % MOD;
  }
  return res;
}

int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(nullptr);
  int T;
  cin >> T;
  for (int t = 1; t <= T; t++) {
    cout << "Case #" << t << ": " << solve() << endl;
  }
  return 0;
}