oj.uz

Submission #956262

# Submission time Handle Problem Language Result Execution time Memory
956262 2024-04-01T12:30:18 Z chrisvilches Dragon 2 (JOI17_dragon2) C++14
100 / 100
 3371 ms 5216 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;

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()) {
      const 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;

      // TODO: Improve range of loop (make it smaller)
      for (const auto& q : points2) {
        if (q.above()) {
          total += q.cross(p) > 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) {
        if (!q.above()) {
          total += 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) {

    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.
    const int big_query = N / 2;



    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();

      if (true) {
        const int ans =
            handle_query(tribe_points.at(i), tribe_points.at(j), order_by_b.at(j), B, j);
        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:221:15: warning: unused variable 'big_query' [-Wunused-variable]
  221 |     const int big_query = N / 2;
      |               ^~~~~~~~~
dragon2.cpp:151:7: warning: unused variable 't' [-Wunused-variable]
  151 |   int t = 0;
      |       ^

Subtask #1
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 600 KB Output is correct
2 Correct 13 ms 604 KB Output is correct
3 Correct 25 ms 688 KB Output is correct
4 Correct 33 ms 1640 KB Output is correct
5 Correct 22 ms 1896 KB Output is correct
6 Correct 2 ms 860 KB Output is correct
7 Correct 2 ms 732 KB Output is correct
8 Correct 4 ms 604 KB Output is correct
9 Correct 6 ms 604 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 430 ms 1984 KB Output is correct
2 Correct 839 ms 1968 KB Output is correct
3 Correct 33 ms 2140 KB Output is correct
4 Correct 11 ms 2136 KB Output is correct
5 Correct 15 ms 3928 KB Output is correct
6 Correct 513 ms 1996 KB Output is correct
7 Correct 550 ms 2004 KB Output is correct
8 Correct 230 ms 1756 KB Output is correct
9 Correct 532 ms 1796 KB Output is correct
10 Correct 231 ms 1724 KB Output is correct

Subtask #3
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 600 KB Output is correct
2 Correct 13 ms 604 KB Output is correct
3 Correct 25 ms 688 KB Output is correct
4 Correct 33 ms 1640 KB Output is correct
5 Correct 22 ms 1896 KB Output is correct
6 Correct 2 ms 860 KB Output is correct
7 Correct 2 ms 732 KB Output is correct
8 Correct 4 ms 604 KB Output is correct
9 Correct 6 ms 604 KB Output is correct
10 Correct 3 ms 348 KB Output is correct
11 Correct 430 ms 1984 KB Output is correct
12 Correct 839 ms 1968 KB Output is correct
13 Correct 33 ms 2140 KB Output is correct
14 Correct 11 ms 2136 KB Output is correct
15 Correct 15 ms 3928 KB Output is correct
16 Correct 513 ms 1996 KB Output is correct
17 Correct 550 ms 2004 KB Output is correct
18 Correct 230 ms 1756 KB Output is correct
19 Correct 532 ms 1796 KB Output is correct
20 Correct 231 ms 1724 KB Output is correct
21 Correct 427 ms 1988 KB Output is correct
22 Correct 875 ms 2132 KB Output is correct
23 Correct 1064 ms 2384 KB Output is correct
24 Correct 585 ms 3176 KB Output is correct
25 Correct 46 ms 3664 KB Output is correct
26 Correct 35 ms 5204 KB Output is correct
27 Correct 14 ms 4700 KB Output is correct
28 Correct 14 ms 4592 KB Output is correct
29 Correct 3371 ms 4808 KB Output is correct
30 Correct 67 ms 5020 KB Output is correct
31 Correct 34 ms 4944 KB Output is correct
32 Correct 54 ms 4944 KB Output is correct
33 Correct 414 ms 5008 KB Output is correct
34 Correct 33 ms 4948 KB Output is correct
35 Correct 36 ms 5216 KB Output is correct
36 Correct 34 ms 4956 KB Output is correct
37 Correct 35 ms 5200 KB Output is correct
38 Correct 646 ms 4944 KB Output is correct
39 Correct 508 ms 4856 KB Output is correct
40 Correct 432 ms 4920 KB Output is correct
41 Correct 2875 ms 4840 KB Output is correct
42 Correct 1402 ms 5092 KB Output is correct
43 Correct 869 ms 4976 KB Output is correct
44 Correct 2016 ms 3568 KB Output is correct
45 Correct 1044 ms 3180 KB Output is correct
46 Correct 655 ms 3276 KB Output is correct
47 Correct 1882 ms 3296 KB Output is correct
48 Correct 1260 ms 3180 KB Output is correct
49 Correct 711 ms 3156 KB Output is correct