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답안 #955976

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
955976 2024-03-31T18:31:47 Z chrisvilches Dragon 2 (JOI17_dragon2) C++14
60 / 100
 4000 ms 4816 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};

    // 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

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 348 KB Output is correct
2 Correct 4 ms 348 KB Output is correct
3 Correct 19 ms 344 KB Output is correct
4 Correct 38 ms 604 KB Output is correct
5 Correct 23 ms 972 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

# 결과 실행 시간 메모리 Grader output
1 Correct 16 ms 1168 KB Output is correct
2 Correct 42 ms 1116 KB Output is correct
3 Correct 16 ms 1512 KB Output is correct
4 Correct 12 ms 1372 KB Output is correct
5 Correct 14 ms 4000 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 1244 KB Output is correct
9 Correct 10 ms 1320 KB Output is correct
10 Correct 12 ms 1208 KB Output is correct

Subtask #3
0 / 40.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 348 KB Output is correct
2 Correct 4 ms 348 KB Output is correct
3 Correct 19 ms 344 KB Output is correct
4 Correct 38 ms 604 KB Output is correct
5 Correct 23 ms 972 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 16 ms 1168 KB Output is correct
12 Correct 42 ms 1116 KB Output is correct
13 Correct 16 ms 1512 KB Output is correct
14 Correct 12 ms 1372 KB Output is correct
15 Correct 14 ms 4000 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 1244 KB Output is correct
19 Correct 10 ms 1320 KB Output is correct
20 Correct 12 ms 1208 KB Output is correct
21 Correct 17 ms 1244 KB Output is correct
22 Correct 43 ms 1220 KB Output is correct
23 Correct 270 ms 1372 KB Output is correct
24 Correct 388 ms 1732 KB Output is correct
25 Correct 51 ms 2392 KB Output is correct
26 Correct 38 ms 4364 KB Output is correct
27 Correct 16 ms 4816 KB Output is correct
28 Correct 16 ms 4808 KB Output is correct
29 Execution timed out 4054 ms 4560 KB Time limit exceeded
30 Halted 0 ms 0 KB -