oj.uz

답안 #956787

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
956787 2024-04-02T13:06:51 Z chrisvilches Dragon 2 (JOI17_dragon2) C++14
100 / 100
 695 ms 29868 KB 
#include <bits/stdc++.h>
using namespace std;

struct Point {
  int x, y, idx, tribe;
  Point operator-(const Point p) const { return {x - p.x, y - p.y, idx, tribe}; }
  Point operator+(const Point p) const { return {x + p.x, y + p.y, idx, tribe}; }
  long long cross(const Point p) const { return x * (long long)p.y - y * (long long)p.x; }
  Point negate() const { return {-x, -y, idx, tribe}; }
};

template <class T, unsigned int N>
struct BIT {
  void clear(const int n) { memset(bit, 0, sizeof(T) * n); }

  T sum(int l, int r) { return sum(r) - sum(l - 1); }

  void add(unsigned int idx, const T delta) {
    for (; idx < N; idx = idx | (idx + 1)) bit[idx] += delta;
  }

 private:
  T bit[N];

  T sum(int r) {
    T ret = 0;
    for (; r >= 0; r = (r & (r + 1)) - 1) ret += bit[r];
    return ret;
  }
};

BIT<int, 30'001> bit;
Point A, B;
vector<unordered_map<int, int>> ans;
vector<vector<Point>> tribe_points, order_by_b;

bool above(const Point p) { return B.cross(p) > 0; }

Point to_upper(const Point p) { return above(p) ? p : p.negate(); }

bool operator<(const Point p, const Point q) {
  return to_upper(p).cross(to_upper(q)) > 0;
}

bool cmp_by_b(const Point p, const Point q) {
  const bool a1 = above(p);
  const bool a2 = above(q);
  if (a1 != a2) return a1;
  return p.cross(q) > 0;
}

// TODO: Make sure the namings make sense. How queries work is a bit confusing.
void query_attacked(const vector<Point>& attacked, const int attacker_idx) {
  const vector<Point>& attackers = tribe_points[attacker_idx];
  const vector<Point>& ord = order_by_b[attacker_idx];

  bit.clear(attackers.size());

  int j = 0;

  for (const Point p : attacked) {
    int total = 0;

    while (j < (int)attackers.size() && attackers[j] < p) {
      bit.add(attackers[j].idx, 1);
      j++;
    }

    const auto mid = lower_bound(ord.begin(), ord.end(), B.negate(), cmp_by_b);

    // TODO: Maybe prepopulating the lower half can simplify this code?
    if (above(p)) {
      const int a = lower_bound(ord.begin(), mid, p - B, cmp_by_b) - ord.begin();
      const auto it = lower_bound(mid, ord.end(), B - p, cmp_by_b);

      total += a - bit.sum(0, a - 1);
      total += it - mid;
      total -= bit.sum(mid - ord.begin(), it - ord.begin() - 1);

    } else {
      const int a = lower_bound(ord.begin(), ord.end(), p - B, cmp_by_b) - ord.begin();
      const int b = lower_bound(ord.begin(), mid, B - p, cmp_by_b) - ord.begin();

      total += bit.sum(a, ord.size() - 1);
      total += bit.sum(b, mid - ord.begin() - 1);
    }

    ans[attacker_idx][p.tribe] += total;
  }
}

void query_attacks(const vector<Point>& attackers, const int attacked_idx) {
  const vector<Point>& attacked = tribe_points[attacked_idx];
  const vector<Point>& ord = order_by_b[attacked_idx];

  bit.clear(attacked.size());

  for (const auto q : attacked) {
    if (!above(q)) bit.add(q.idx, 1);
  }

  int j = 0;

  for (const Point p : attackers) {
    while (j < (int)attacked.size() && attacked[j] < p) {
      const Point q = attacked[j];
      bit.add(q.idx, above(q) ? 1 : -1);
      j++;
    }

    const Point v = above(p) ? p - B : B - p;

    const int a = lower_bound(ord.begin(), ord.end(), v, cmp_by_b) - ord.begin();
    const int b = lower_bound(ord.begin(), ord.end(), v.negate(), cmp_by_b) - ord.begin();

    ans[p.tribe][attacked_idx] += bit.sum(a, b - 1);
  }
}

void handle_all_queries(const map<int, set<int>>& attacks,
                        const map<int, set<int>>& attacked) {
  vector<tuple<long long, int, bool>> queries;

  const auto add_weighted_query = [&](const auto& q, const bool is_attack) {
    const auto [tribe_idx, other] = q;
    const long long weight = tribe_points[tribe_idx].size() * other.size();
    queries.emplace_back(weight, tribe_idx, is_attack);
  };

  for (const auto& q : attacks) add_weighted_query(q, true);
  for (const auto& q : attacked) add_weighted_query(q, false);

  sort(queries.rbegin(), queries.rend());

  for (const auto& [_, tribe_idx, is_attack] : queries) {
    vector<Point> all_points;

    const auto& other_tribes = (is_attack ? attacks : attacked).at(tribe_idx);

    for (const int other_tribe_idx : other_tribes) {
      int i = tribe_idx, j = other_tribe_idx;
      if (!is_attack) swap(i, j);

      if (ans[i].count(j)) continue;

      for (const Point p : tribe_points[other_tribe_idx]) {
        all_points.emplace_back(p);
      }

      ans[i][j] = 0;
    }

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

    // TODO: This is weird. Shouldn't it be is_attack -> query_attacks ????
    if (is_attack) {
      query_attacked(all_points, tribe_idx);
    } else {
      query_attacks(all_points, tribe_idx);
    }
  }
}

int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  int N, M, Q;

  while (cin >> N >> M) {
    tribe_points.assign(M + 1, vector<Point>());
    order_by_b.assign(M + 1, vector<Point>());
    ans.assign(M + 1, unordered_map<int, int>());

    for (int i = 0; i < N; i++) {
      Point p;
      cin >> p.x >> p.y >> p.tribe;
      tribe_points[p.tribe].push_back(p);
    }

    cin >> A.x >> A.y >> B.x >> B.y;
    cin >> Q;
    B = B - A;

    for (int m = 0; m <= M; m++) {
      auto& points = tribe_points[m];
      for (auto& p : points) p = p - A;
      for (auto& p : points) p = p - B;
      sort(points.begin(), points.end(), cmp_by_b);
      for (int i = 0; i < (int)points.size(); i++) points[i].idx = i;
      auto& b = order_by_b[m];
      b = points;
      for (auto& p : points) p = p + B;
      sort(points.begin(), points.end());
    }

    map<int, set<int>> attacks, attacked;
    vector<pair<int, int>> query_original_order;

    while (Q--) {
      int i, j;
      cin >> i >> j;
      attacks[i].emplace(j);
      attacked[j].emplace(i);
      query_original_order.emplace_back(i, j);
    }

    handle_all_queries(attacks, attacked);

    for (const auto& [i, j] : query_original_order) {
      cout << ans[i][j] << '\n';
    }
  }
}

Compilation message

dragon2.cpp: In lambda function:
dragon2.cpp:125:16: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
  125 |     const auto [tribe_idx, other] = q;
      |                ^
dragon2.cpp: In function 'void handle_all_queries(const std::map<int, std::set<int> >&, const std::map<int, std::set<int> >&)':
dragon2.cpp:135:20: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
  135 |   for (const auto& [_, tribe_idx, is_attack] : queries) {
      |                    ^
dragon2.cpp: In function 'int main()':
dragon2.cpp:209:22: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
  209 |     for (const auto& [i, j] : query_original_order) {
      |                      ^

Subtask #1
15.0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 604 KB Output is correct
2 Correct 5 ms 604 KB Output is correct
3 Correct 35 ms 1612 KB Output is correct
4 Correct 151 ms 16324 KB Output is correct
5 Correct 126 ms 17352 KB Output is correct
6 Correct 3 ms 1624 KB Output is correct
7 Correct 3 ms 1628 KB Output is correct
8 Correct 2 ms 604 KB Output is correct
9 Correct 2 ms 560 KB Output is correct
10 Correct 1 ms 604 KB Output is correct

Subtask #2
45.0 / 45.0

# 결과 실행 시간 메모리 Grader output
1 Correct 19 ms 2456 KB Output is correct
2 Correct 57 ms 2956 KB Output is correct
3 Correct 20 ms 2396 KB Output is correct
4 Correct 12 ms 2396 KB Output is correct
5 Correct 13 ms 5712 KB Output is correct
6 Correct 15 ms 2396 KB Output is correct
7 Correct 15 ms 2396 KB Output is correct
8 Correct 16 ms 2396 KB Output is correct
9 Correct 12 ms 2272 KB Output is correct
10 Correct 11 ms 2264 KB Output is correct

Subtask #3
40.0 / 40.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 604 KB Output is correct
2 Correct 5 ms 604 KB Output is correct
3 Correct 35 ms 1612 KB Output is correct
4 Correct 151 ms 16324 KB Output is correct
5 Correct 126 ms 17352 KB Output is correct
6 Correct 3 ms 1624 KB Output is correct
7 Correct 3 ms 1628 KB Output is correct
8 Correct 2 ms 604 KB Output is correct
9 Correct 2 ms 560 KB Output is correct
10 Correct 1 ms 604 KB Output is correct
11 Correct 19 ms 2456 KB Output is correct
12 Correct 57 ms 2956 KB Output is correct
13 Correct 20 ms 2396 KB Output is correct
14 Correct 12 ms 2396 KB Output is correct
15 Correct 13 ms 5712 KB Output is correct
16 Correct 15 ms 2396 KB Output is correct
17 Correct 15 ms 2396 KB Output is correct
18 Correct 16 ms 2396 KB Output is correct
19 Correct 12 ms 2272 KB Output is correct
20 Correct 11 ms 2264 KB Output is correct
21 Correct 20 ms 2392 KB Output is correct
22 Correct 57 ms 3064 KB Output is correct
23 Correct 416 ms 3828 KB Output is correct
24 Correct 695 ms 18112 KB Output is correct
25 Correct 203 ms 21796 KB Output is correct
26 Correct 215 ms 29440 KB Output is correct
27 Correct 33 ms 13264 KB Output is correct
28 Correct 32 ms 13136 KB Output is correct
29 Correct 237 ms 29792 KB Output is correct
30 Correct 182 ms 28480 KB Output is correct
31 Correct 201 ms 29184 KB Output is correct
32 Correct 203 ms 29788 KB Output is correct
33 Correct 465 ms 28484 KB Output is correct
34 Correct 239 ms 29240 KB Output is correct
35 Correct 202 ms 29868 KB Output is correct
36 Correct 219 ms 28740 KB Output is correct
37 Correct 215 ms 29504 KB Output is correct
38 Correct 530 ms 29004 KB Output is correct
39 Correct 546 ms 28896 KB Output is correct
40 Correct 505 ms 28424 KB Output is correct
41 Correct 228 ms 29124 KB Output is correct
42 Correct 252 ms 29060 KB Output is correct
43 Correct 280 ms 28860 KB Output is correct
44 Correct 33 ms 8076 KB Output is correct
45 Correct 32 ms 7900 KB Output is correct
46 Correct 33 ms 7884 KB Output is correct
47 Correct 35 ms 9592 KB Output is correct
48 Correct 35 ms 9432 KB Output is correct
49 Correct 35 ms 9356 KB Output is correct