oj.uz

Submission #956273

# Submission time Handle Problem Language Result Execution time Memory
956273 2024-04-01T12:55:58 Z chrisvilches Dragon 2 (JOI17_dragon2) C++14
100 / 100
 2291 ms 5232 KB 
#include <bits/stdc++.h>
using namespace std;
using ll = int;

ll Bx, By;

map<pair<int, int>, int> query_ans;

vector<vector<int>> upper_triangles;

// TODO: Idea super dificil de implementar: Crear un arbol de convex hulls en ord_b
//       Para poder acceder a informacion global (por ejemplo saber cuantos puntos hay
//       dentro del convex hull y si ese poligono cabe dentro de un triangulo, etc). No se
//       si sirva de algo.

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 Bx * (long long)y - By * (long long)x > 0;
    // 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;
// }

vector<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, const int attacked_idx) {
  if (points1.empty() || points2.empty()) return 0;

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

  // const int n = points2.size();

  // int points_above = 0;
  // int points_below = 0;

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

  const auto mid = lower_bound(ord_b.begin(), ord_b.end(), (Point{0, 0} - B), cmp_by_b);

  int total = 0;

  // query_ans[{1, 1}] = 1;
  // auto& ref = query_ans.at({1, 1});

  int points_activated_above = 0;
  int points_deactivated_below = 0;

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

      if (!(q < p)) break;
      // add(q.idx, q.above() ? 1 : -1);

      if (q.above()) points_activated_above++;
      if (!q.above()) points_deactivated_below++;

      j++;
    }

    Point from_point = p;
    Point to_point = B;
    to_point.x += B.x - p.x;
    to_point.y += B.y - p.y;

    if (p.above()) {
      auto it2 = lower_bound(mid, ord_b.end(), to_point - B, cmp_by_b);

      const int below_to_angle = it2 - mid;
      const int activated_below = below_to_angle - points_deactivated_below;
      total += activated_below;

      // for (auto it = mid; it != ord_b.end(); it--) {
      //   if (it == ord_b.end()) break;
      //   const Point q = *it + B;
      //   if (!q.above()) continue;
      //   // if (q.above()) {
      //   assert(q.above());
      //   total += q.cross(p) > 0 && orientation(B, p, q) > 0;
      //   // }
      //   if (it == ord_b.begin()) break;
      //   if (orientation(B, q, p) > 0) break;
      // }

      // TODO: Improve range of loop (make it smaller)
      for (const auto& q : points2) {
        total += q.above() && p.cross(q) < 0 && orientation(B, p, q) > 0;
      }

    } else {
      swap(from_point, to_point);
      const auto it2 = lower_bound(ord_b.begin(), mid, B - p, cmp_by_b);
      const int above_to_angle = it2 - ord_b.begin();
      const int activated_above = points_activated_above - above_to_angle;
      total += activated_above;

      for (const auto& q : points2) {
        total += !q.above() && p.cross(q) > 0 && orientation(B, p, q) < 0;
      }
    }
  }
  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);
    order_by_b = vector<vector<Point>>(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};

    // upper_triangles.assign(M + 1, vector<int>());

    // for (int m = 0; m <= M; m++) {
    //   clear(30'000);
    //   const auto& ord_b = order_by_b[m];
    //   for (const auto& p : tribe_points[m]) {
    //     if (!p.above()) {
    //       upper_triangles[m].emplace_back(0);
    //       continue;
    //     }

    //     add(p.idx, 1);
    //     upper_triangles[m].emplace_back(sum(p.idx, 30'000));
    //   }
    //   assert(ord_b.size() == upper_triangles[m].size());
    // }

    // TODO: Are the fenwick queries actually faster???? DO some experiments

    // TODO: Set this value more properly, and explain that this doesn't really help
    //       but it's something. (assuming fenwick is ACTUALLY faster)

    // TODO: Comment that this solution is probably not the intended one. The example
    // solution is much faster (under a second).
    // TODO: The thing is, I don't want to leave this code without the radial sweep, I
    // want to add it for the lulz.

    clock_t begin = clock();

    while (Q--) {
      int i, j;
      cin >> i >> j;
      // cerr << tribe_points[i].size() * tribe_points[j].size() << endl;
      // const long long size = tribe_points[i].size() * tribe_points[j].size();

      const int ans =
          handle_query(tribe_points.at(i), tribe_points.at(j), order_by_b.at(j), B, j);
      cout << ans << '\n';
    }
    clock_t end = clock();
    double elapsed_secs = double(end - begin) / CLOCKS_PER_SEC;
    cerr << fixed << setprecision(3) << "   time: " << elapsed_secs << endl;

    t++;
  }
}

Compilation message

dragon2.cpp: In function 'int main()':
dragon2.cpp:206:17: warning: unused variable 'origin' [-Wunused-variable]
  206 |     const Point origin{0, 0, -1};
      |                 ^~~~~~

Subtask #1
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 344 KB Output is correct
2 Correct 11 ms 600 KB Output is correct
3 Correct 22 ms 600 KB Output is correct
4 Correct 31 ms 1620 KB Output is correct
5 Correct 28 ms 2128 KB Output is correct
6 Correct 2 ms 860 KB Output is correct
7 Correct 2 ms 728 KB Output is correct
8 Correct 4 ms 460 KB Output is correct
9 Correct 6 ms 344 KB Output is correct
10 Correct 3 ms 348 KB Output is correct

Subtask #2
45.0 / 45.0

# Verdict Execution time Memory Grader output
1 Correct 436 ms 1172 KB Output is correct
2 Correct 885 ms 2128 KB Output is correct
3 Correct 35 ms 2136 KB Output is correct
4 Correct 11 ms 2140 KB Output is correct
5 Correct 12 ms 3932 KB Output is correct
6 Correct 518 ms 1976 KB Output is correct
7 Correct 558 ms 1968 KB Output is correct
8 Correct 235 ms 2012 KB Output is correct
9 Correct 482 ms 1772 KB Output is correct
10 Correct 240 ms 1780 KB Output is correct

Subtask #3
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 344 KB Output is correct
2 Correct 11 ms 600 KB Output is correct
3 Correct 22 ms 600 KB Output is correct
4 Correct 31 ms 1620 KB Output is correct
5 Correct 28 ms 2128 KB Output is correct
6 Correct 2 ms 860 KB Output is correct
7 Correct 2 ms 728 KB Output is correct
8 Correct 4 ms 460 KB Output is correct
9 Correct 6 ms 344 KB Output is correct
10 Correct 3 ms 348 KB Output is correct
11 Correct 436 ms 1172 KB Output is correct
12 Correct 885 ms 2128 KB Output is correct
13 Correct 35 ms 2136 KB Output is correct
14 Correct 11 ms 2140 KB Output is correct
15 Correct 12 ms 3932 KB Output is correct
16 Correct 518 ms 1976 KB Output is correct
17 Correct 558 ms 1968 KB Output is correct
18 Correct 235 ms 2012 KB Output is correct
19 Correct 482 ms 1772 KB Output is correct
20 Correct 240 ms 1780 KB Output is correct
21 Correct 474 ms 1752 KB Output is correct
22 Correct 902 ms 1960 KB Output is correct
23 Correct 1053 ms 2476 KB Output is correct
24 Correct 537 ms 3152 KB Output is correct
25 Correct 41 ms 3664 KB Output is correct
26 Correct 34 ms 5232 KB Output is correct
27 Correct 14 ms 4696 KB Output is correct
28 Correct 14 ms 4700 KB Output is correct
29 Correct 2291 ms 5008 KB Output is correct
30 Correct 58 ms 4924 KB Output is correct
31 Correct 34 ms 4876 KB Output is correct
32 Correct 51 ms 4952 KB Output is correct
33 Correct 376 ms 4988 KB Output is correct
34 Correct 33 ms 4952 KB Output is correct
35 Correct 32 ms 4948 KB Output is correct
36 Correct 33 ms 4852 KB Output is correct
37 Correct 34 ms 5200 KB Output is correct
38 Correct 585 ms 4948 KB Output is correct
39 Correct 475 ms 4836 KB Output is correct
40 Correct 403 ms 4948 KB Output is correct
41 Correct 2176 ms 5192 KB Output is correct
42 Correct 1087 ms 4652 KB Output is correct
43 Correct 697 ms 4664 KB Output is correct
44 Correct 2114 ms 3256 KB Output is correct
45 Correct 1048 ms 2908 KB Output is correct
46 Correct 682 ms 3060 KB Output is correct
47 Correct 658 ms 3008 KB Output is correct
48 Correct 659 ms 3072 KB Output is correct
49 Correct 286 ms 3164 KB Output is correct