結果

問題 No.2769 Number of Rhombi
ユーザー risujirohrisujiroh
提出日時 2024-05-31 22:10:03
言語 C++23
(gcc 13.3.0 + boost 1.87.0)
結果
AC  
実行時間 175 ms / 5,000 ms
コード長 4,883 bytes
コンパイル時間 3,937 ms
コンパイル使用メモリ 285,516 KB
実行使用メモリ 20,856 KB
最終ジャッジ日時 2024-12-20 23:41:30
合計ジャッジ時間 10,048 ms
ジャッジサーバーID
（参考情報） 		judge5 / judge2
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ファイルパターン 結果
sample AC * 3
other AC * 32
権限があれば一括ダウンロードができます

ソースコード

diff # 

#if __INCLUDE_LEVEL__ == 0

#include __BASE_FILE__

namespace {

void solve() {
  Int n;
  scan(n);
  Vec<Int> x(n), y(n);
  for (const Int i : rep(n)) {
    scan(x[i], y[i]);
  }
  std::vector<Pair<Pair<Int, Int>, Pair<Int, Int>>> v;
  for (const Int i : rep(n)) {
    for (const Int j : rep(i + 1, n)) {
      const Int sx = x[i] + x[j];
      const Int sy = y[i] + y[j];
      Int dx = x[j] - x[i];
      Int dy = y[j] - y[i];
      if (dy < 0 || (dy == 0 && dx < 0)) {
        dx = -dx;
        dy = -dy;
      }
      const Int g = std::gcd(dx, dy);
      dx /= g;
      dy /= g;
      v.emplace_back(Pair(sx, sy), Pair(dx, dy));
    }
  }
  ranges::sort(v);
  Int ans = 0;
  for (Int l = 0; l < len(v);) {
    Int r = l + 1;
    while (r < len(v) && v[l].first == v[r].first) {
      ++r;
    }
    Vec<Pair<Int, Int>> w;
    for (auto [dx, dy] :
         v | views::drop(l) | views::take(r - l) | views::values) {
      std::tie(dx, dy) = Pair(dy, -dx);
      if (dy < 0 || (dy == 0 && dx < 0)) {
        dx = -dx;
        dy = -dy;
      }
      w.emplace_back(dx, dy);
    }
    ranges::sort(w);
    auto it = w.begin();
    auto it2 = w.begin();
    for (const auto& p :
         v | views::drop(l) | views::take(r - l) | views::values) {
      while (it != w.end() && *it < p) {
        ++it;
      }
      while (it2 != w.end() && *it2 <= p) {
        ++it2;
      }
      ans += it2 - it;
    }
    l = r;
  }
  ans /= 2;
  print(ans);
}

}  // namespace

int main() {
  std::ios::sync_with_stdio(false);
  std::cin.tie(nullptr);
  std::cout << std::setprecision(std::numeric_limits<Float>::max_digits10);

  solve();
}

#else  // __INCLUDE_LEVEL__

#include <bits/stdc++.h>

using i8 = int8_t;
using i16 = int16_t;
using i32 = int32_t;
using i64 = int64_t;
using i128 = __int128_t;
using u8 = uint8_t;
using u16 = uint16_t;
using u32 = uint32_t;
using u64 = uint64_t;
using u128 = __uint128_t;

using Int = int64_t;
using Float = double;
using Str = std::string;

template <class T1, class T2>
using Pair = std::pair<T1, T2>;

template <class... Ts>
using Tuple = std::tuple<Ts...>;

template <class T, size_t N>
using Arr = std::array<T, N>;

template <class T>
using Vec = std::vector<T>;

template <class T>
using Set = std::set<T>;

template <class T>
using Multiset = std::multiset<T>;

template <class K, class T>
using Map = std::map<K, T>;

template <class T>
using MinHeap = std::priority_queue<T, Vec<T>, std::greater<T>>;

template <class T>
using MaxHeap = std::priority_queue<T>;

namespace ranges = std::ranges;
namespace views = std::views;

inline constexpr auto len = ranges::ssize;
inline constexpr auto rev = views::reverse;

constexpr auto rep(Int l, Int r) { return views::iota(std::min(l, r), r); }
constexpr auto rep(Int n) { return rep(0, n); }
constexpr auto rep1(Int l, Int r) { return rep(l, r + 1); }
constexpr auto rep1(Int n) { return rep(1, n + 1); }

template <class T, class U = T>
bool chmin(T& x, U&& y) {
  return y < x && (x = std::forward<U>(y), true);
}

template <class T, class U = T>
bool chmax(T& x, U&& y) {
  return x < y && (x = std::forward<U>(y), true);
}

template <std::signed_integral T = Int>
T inf() {
  T ret;
  std::memset(&ret, 0x3f, sizeof(ret));
  return ret;
}

template <std::floating_point T>
T inf() {
  return std::numeric_limits<T>::infinity();
}

template <class T>
concept Range = ranges::range<T> && !std::convertible_to<T, std::string_view>;

template <class T>
concept TupleLike = std::__is_tuple_like<T>::value && !Range<T>;

namespace std {

istream& operator>>(istream& is, Range auto&& r) {
  for (auto&& e : r) {
    is >> e;
  }
  return is;
}

istream& operator>>(istream& is, TupleLike auto&& t) {
  return apply([&](auto&... xs) -> istream& { return (is >> ... >> xs); }, t);
}

ostream& operator<<(ostream& os, Range auto&& r) {
  for (string_view sep = ""; auto&& e : r) {
    os << exchange(sep, " ") << e;
  }
  return os;
}

ostream& operator<<(ostream& os, TupleLike auto&& t) {
  const auto f = [&](auto&... xs) -> ostream& {
    [[maybe_unused]] string_view sep = "";
    ((os << exchange(sep, " ") << xs), ...);
    return os;
  };
  return apply(f, t);
}

}  // namespace std

#define DEF_INC_OR_DEC(op) \
  auto& operator op(Range auto&& r) { \
    for (auto&& e : r) { \
      op e; \
    } \
    return r; \
  } \
  auto& operator op(TupleLike auto&& t) { \
    std::apply([](auto&... xs) { (op xs, ...); }, t); \
    return t; \
  }

DEF_INC_OR_DEC(++)
DEF_INC_OR_DEC(--)

#undef DEF_INC_OR_DEC

void scan(auto&&... xs) { std::cin >> std::tie(xs...); }
void print(auto&&... xs) { std::cout << std::tie(xs...) << '\n'; }

template <class F>
class fix {
 public:
  explicit fix(F f) : f_(std::move(f)) {}

  decltype(auto) operator()(auto&&... xs) const {
    return f_(std::ref(*this), std::forward<decltype(xs)>(xs)...);
  }

 private:
  F f_;
};

#endif  // __INCLUDE_LEVEL__
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