oj.uz

Submission #955963

# Submission time Handle Problem Language Result Execution time Memory
955963 2024-03-31T18:12:25 Z chrisvilches Dragon 2 (JOI17_dragon2) C++14
100 / 100
 3161 ms 4792 KB 
#include <bits/stdc++.h>
using namespace std;
using ll = int;

ll Bx, By;

struct Point {
  ll x, y;
  int idx;
  inline Point operator-(const Point p) const { return {x - p.x, y - p.y, idx}; }
  inline Point operator+(const Point p) const { return {x + p.x, y + p.y, idx}; }
  inline long long cross(const Point p) const {
    return x * (long long)p.y - y * (long long)p.x;
  }
  inline bool operator<(const Point p) const {
    return to_upper().cross(p.to_upper()) > 0;
  }
  inline Point to_upper() const { return above() ? *this : negate(); }
  inline bool above() const {
    // TODO: Improve this
    const Point B{Bx, By, idx};
    return B.cross(*this) > 0;
  }
  inline Point negate() const { return {-x, -y, idx}; }
};

short orientation(const Point& o, const Point& a, const Point& b) {
  // assert((a - o).cross(b - o) != 0);
  const long long x = (a - o).cross(b - o);
  return (x > 0) - (x < 0);
}

short bit[30'001];
int bit_n = 30'001;

void clear(const int n) { memset(bit, 0, sizeof(short) * n); }

// TODO: Return should be int, not short.
int sum_single(int r) {
  int ret = 0;
  for (; r >= 0; r = (r & (r + 1)) - 1) ret += bit[r];
  return ret;
}

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

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

unordered_map<int, vector<Point>> order_by_b;

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

int handle_query(const vector<Point>& points1, const vector<Point>& points2,
                 const vector<Point>& ord_b, const Point& B) {
  if (points1.empty() || points2.empty()) return 0;

  bit_n = (int)points2.size();
  clear(points2.size());

  for (const auto& q : points2) {
    if (!q.above()) {
      add(q.idx, 1);
    }
  }

  int total = 0;

  int j = 0;
  for (const Point& p : points1) {
    while (j < (int)points2.size()) {
      const Point& q = points2[j];

      if (q.to_upper().cross(p.to_upper()) < 0) break;
      add(q.idx, q.above() ? 1 : -1);

      j++;
    }

    Point from_point = p;
    Point to_point = B + (p - B).negate();

    if (!p.above()) swap(from_point, to_point);

    // total += 1;
    // continue;

    const auto it1 = lower_bound(ord_b.begin(), ord_b.end(), from_point - B, cmp_by_b);
    const auto it2 = lower_bound(ord_b.begin(), ord_b.end(), to_point - B, cmp_by_b);

    const int from = it1 - ord_b.begin();
    const int to = it2 - ord_b.begin();

    total += sum(from, to - 1);
  }

  return total;
}

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

  int t = 0;
  while (cin >> N >> M) {
    cerr << "--- " << (t++) << endl;
    vector<vector<Point>> tribe_points(M + 1);
    for (int i = 0; i < N; i++) {
      Point p;
      int tribe;
      cin >> p.x >> p.y >> tribe;
      tribe_points[tribe].push_back(p);
    }

    Point A;
    cin >> A.x >> A.y;
    cin >> Bx >> By;
    cin >> Q;

    Bx -= A.x;
    By -= A.y;

    for (auto& points : tribe_points) {
      for (auto& p : points) p = p - A;
    }

    const Point B{Bx, By, -1};

    for (int m = 0; m <= M; m++) {
      auto& points = tribe_points[m];

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

    for (auto& points : tribe_points) {
      sort(points.begin(), points.end());
    }

    const Point origin{0, 0, -1};

    int fast_queries = 50'000;
    const int big_query = sqrt(N);

    while (Q--) {
      int i, j;
      cin >> i >> j;

      if ((int)tribe_points[j].size() > big_query) {
        const int ans =
            handle_query(tribe_points.at(i), tribe_points.at(j), order_by_b.at(j), B);
        cout << ans << '\n';
      } else {
        int total = 0;
        for (const Point& p : tribe_points[i]) {
          for (const Point& q : tribe_points[j]) {
            if (orientation(origin, B, p) == 1) {
              if (orientation(B, p, q) == 1 && orientation(p, origin, q) == 1) total++;
            } else {
              if (orientation(origin, p, q) == 1 && orientation(p, B, q) == 1) total++;
            }
          }
        }
        cout << total << '\n';
      }
    }
  }
}

Compilation message

dragon2.cpp: In function 'int main()':
dragon2.cpp:154:9: warning: unused variable 'fast_queries' [-Wunused-variable]
  154 |     int fast_queries = 50'000;
      |         ^~~~~~~~~~~~

Subtask #1
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 348 KB Output is correct
2 Correct 4 ms 348 KB Output is correct
3 Correct 20 ms 348 KB Output is correct
4 Correct 27 ms 600 KB Output is correct
5 Correct 21 ms 860 KB Output is correct
6 Correct 2 ms 860 KB Output is correct
7 Correct 2 ms 860 KB Output is correct
8 Correct 2 ms 348 KB Output is correct
9 Correct 1 ms 348 KB Output is correct
10 Correct 1 ms 348 KB Output is correct

Subtask #2
45.0 / 45.0

# Verdict Execution time Memory Grader output
1 Correct 17 ms 1312 KB Output is correct
2 Correct 43 ms 1116 KB Output is correct
3 Correct 17 ms 1372 KB Output is correct
4 Correct 14 ms 1240 KB Output is correct
5 Correct 13 ms 4024 KB Output is correct
6 Correct 13 ms 1080 KB Output is correct
7 Correct 13 ms 1500 KB Output is correct
8 Correct 15 ms 1216 KB Output is correct
9 Correct 10 ms 1244 KB Output is correct
10 Correct 9 ms 1212 KB Output is correct

Subtask #3
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 348 KB Output is correct
2 Correct 4 ms 348 KB Output is correct
3 Correct 20 ms 348 KB Output is correct
4 Correct 27 ms 600 KB Output is correct
5 Correct 21 ms 860 KB Output is correct
6 Correct 2 ms 860 KB Output is correct
7 Correct 2 ms 860 KB Output is correct
8 Correct 2 ms 348 KB Output is correct
9 Correct 1 ms 348 KB Output is correct
10 Correct 1 ms 348 KB Output is correct
11 Correct 17 ms 1312 KB Output is correct
12 Correct 43 ms 1116 KB Output is correct
13 Correct 17 ms 1372 KB Output is correct
14 Correct 14 ms 1240 KB Output is correct
15 Correct 13 ms 4024 KB Output is correct
16 Correct 13 ms 1080 KB Output is correct
17 Correct 13 ms 1500 KB Output is correct
18 Correct 15 ms 1216 KB Output is correct
19 Correct 10 ms 1244 KB Output is correct
20 Correct 9 ms 1212 KB Output is correct
21 Correct 16 ms 1352 KB Output is correct
22 Correct 43 ms 1112 KB Output is correct
23 Correct 274 ms 1736 KB Output is correct
24 Correct 461 ms 1876 KB Output is correct
25 Correct 44 ms 2392 KB Output is correct
26 Correct 35 ms 4276 KB Output is correct
27 Correct 15 ms 4792 KB Output is correct
28 Correct 15 ms 4788 KB Output is correct
29 Correct 3161 ms 4456 KB Output is correct
30 Correct 70 ms 4020 KB Output is correct
31 Correct 35 ms 4024 KB Output is correct
32 Correct 50 ms 4280 KB Output is correct
33 Correct 432 ms 4392 KB Output is correct
34 Correct 37 ms 4268 KB Output is correct
35 Correct 35 ms 4312 KB Output is correct
36 Correct 38 ms 4280 KB Output is correct
37 Correct 35 ms 4280 KB Output is correct
38 Correct 701 ms 4468 KB Output is correct
39 Correct 585 ms 4272 KB Output is correct
40 Correct 448 ms 4372 KB Output is correct
41 Correct 2651 ms 4436 KB Output is correct
42 Correct 853 ms 4332 KB Output is correct
43 Correct 453 ms 4320 KB Output is correct
44 Correct 1261 ms 2740 KB Output is correct
45 Correct 650 ms 2928 KB Output is correct
46 Correct 364 ms 2648 KB Output is correct
47 Correct 1600 ms 2992 KB Output is correct
48 Correct 1197 ms 2944 KB Output is correct
49 Correct 872 ms 2896 KB Output is correct