oj.uz

Submission #955980

# Submission time Handle Problem Language Result Execution time Memory
955980 2024-03-31T18:36:47 Z chrisvilches Dragon 2 (JOI17_dragon2) C++14
60 / 100
 4000 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;

  const auto middle =
      lower_bound(ord_b.begin(), ord_b.end(), Point{-B.x, -B.y}, cmp_by_b);

  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);

      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(), middle, from_point - B, cmp_by_b);
    const auto it2 = lower_bound(middle, 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;

  while (cin >> N >> M) {
    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};

    // 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).
    const int big_query = N / 2;

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

      if (true || (int)tribe_points[j].size() > big_query) {
        // cerr << tribe_points[j].size() << " > " << big_query << endl;
        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';
      }
    }
  }
}

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 18 ms 564 KB Output is correct
4 Correct 36 ms 808 KB Output is correct
5 Correct 23 ms 1004 KB Output is correct
6 Correct 2 ms 860 KB Output is correct
7 Correct 2 ms 796 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 520 KB Output is correct

Subtask #2
45.0 / 45.0

# Verdict Execution time Memory Grader output
1 Correct 19 ms 1180 KB Output is correct
2 Correct 43 ms 1280 KB Output is correct
3 Correct 17 ms 1368 KB Output is correct
4 Correct 11 ms 1372 KB Output is correct
5 Correct 13 ms 4040 KB Output is correct
6 Correct 13 ms 1244 KB Output is correct
7 Correct 13 ms 1244 KB Output is correct
8 Correct 14 ms 1252 KB Output is correct
9 Correct 10 ms 1244 KB Output is correct
10 Correct 9 ms 1212 KB Output is correct

Subtask #3
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 18 ms 564 KB Output is correct
4 Correct 36 ms 808 KB Output is correct
5 Correct 23 ms 1004 KB Output is correct
6 Correct 2 ms 860 KB Output is correct
7 Correct 2 ms 796 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 520 KB Output is correct
11 Correct 19 ms 1180 KB Output is correct
12 Correct 43 ms 1280 KB Output is correct
13 Correct 17 ms 1368 KB Output is correct
14 Correct 11 ms 1372 KB Output is correct
15 Correct 13 ms 4040 KB Output is correct
16 Correct 13 ms 1244 KB Output is correct
17 Correct 13 ms 1244 KB Output is correct
18 Correct 14 ms 1252 KB Output is correct
19 Correct 10 ms 1244 KB Output is correct
20 Correct 9 ms 1212 KB Output is correct
21 Correct 18 ms 1240 KB Output is correct
22 Correct 43 ms 1116 KB Output is correct
23 Correct 271 ms 1488 KB Output is correct
24 Correct 374 ms 2144 KB Output is correct
25 Correct 50 ms 2332 KB Output is correct
26 Correct 39 ms 4280 KB Output is correct
27 Correct 16 ms 4600 KB Output is correct
28 Correct 16 ms 4792 KB Output is correct
29 Execution timed out 4080 ms 4652 KB Time limit exceeded
30 Halted 0 ms 0 KB -