結果

問題 No.1103 Directed Length Sum
ユーザー KoDKoD
提出日時 2020-07-03 21:25:19
言語 C++17
(gcc 12.3.0 + boost 1.83.0)
結果
AC  
実行時間 1,080 ms / 3,000 ms
コード長 5,209 bytes
コンパイル時間 1,044 ms
コンパイル使用メモリ 84,764 KB
実行使用メモリ 135,392 KB
最終ジャッジ日時 2024-09-16 21:36:06
合計ジャッジ時間 11,419 ms
ジャッジサーバーID
(参考情報)
judge4 / judge2
このコードへのチャレンジ
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テストケース

テストケース表示
入力 結果 実行時間
実行使用メモリ
testcase_00 AC 2 ms
6,812 KB
testcase_01 AC 2 ms
6,940 KB
testcase_02 AC 763 ms
135,392 KB
testcase_03 AC 495 ms
42,376 KB
testcase_04 AC 595 ms
32,112 KB
testcase_05 AC 1,080 ms
53,308 KB
testcase_06 AC 372 ms
22,072 KB
testcase_07 AC 73 ms
7,808 KB
testcase_08 AC 116 ms
10,108 KB
testcase_09 AC 43 ms
6,940 KB
testcase_10 AC 163 ms
12,628 KB
testcase_11 AC 659 ms
34,752 KB
testcase_12 AC 377 ms
22,184 KB
testcase_13 AC 170 ms
12,976 KB
testcase_14 AC 32 ms
6,944 KB
testcase_15 AC 286 ms
18,132 KB
testcase_16 AC 743 ms
38,708 KB
testcase_17 AC 776 ms
40,184 KB
testcase_18 AC 182 ms
12,636 KB
testcase_19 AC 686 ms
35,556 KB
testcase_20 AC 54 ms
6,940 KB
testcase_21 AC 106 ms
9,600 KB
testcase_22 AC 540 ms
29,696 KB
testcase_23 AC 292 ms
18,984 KB
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 #

#include <iostream>
#include <algorithm>
#include <utility>
#include <numeric>
#include <vector>
#include <array>

template <class T, class U>
inline bool chmin(T &lhs, const U &rhs) {
  if (lhs > rhs) { lhs = rhs; return true; }
  return false;
}

template <class T, class U>
inline bool chmax(T &lhs, const U &rhs) {
  if (lhs < rhs) { lhs = rhs; return true; }
  return false;
}

struct range {
  using itr = int64_t;
  struct iterator {
    itr i;
    constexpr iterator(itr i_) noexcept : i(i_) { }
    constexpr void operator ++ () noexcept { ++i; }
    constexpr itr operator * () const noexcept { return i; }
    constexpr bool operator != (iterator x) const noexcept { return i != x.i; }
  };
  const iterator l, r;
  constexpr range(itr l_, itr r_) noexcept : l(l_), r(std::max(l_, r_)) { }
  constexpr iterator begin() const noexcept { return l; }
  constexpr iterator end() const noexcept { return r; }
};

struct revrange {
  using itr = int64_t;
  struct iterator {
    itr i;
    constexpr iterator(itr i_) noexcept : i(i_) { }
    constexpr void operator ++ () noexcept { --i; }
    constexpr itr operator * () const noexcept { return i; }
    constexpr bool operator != (iterator x) const noexcept { return i != x.i; }
  };
  const iterator l, r;
  constexpr revrange(itr l_, itr r_) noexcept : l(l_ - 1), r(std::max(l_, r_) - 1) { }
  constexpr iterator begin() const noexcept { return r; }
  constexpr iterator end() const noexcept { return l; }
};

template <uint32_t Modulus>
class modular {
public:
  using value_type = uint32_t;
  using max_type = uint64_t;

  static constexpr value_type mod = Modulus;
  static constexpr value_type get_mod() { return mod; }
  static_assert(mod >= 2, "invalid mod :: smaller than 2");
  static_assert(mod < (value_type(1) << 31), "invalid mod :: over 2^31");

  template <class T>
  static constexpr value_type normalize(T value_) {
    if (value_ < 0) {
      value_ = -value_;
      value_ %= mod;
      if (value_ == 0) return 0;
      return mod - value_;
    }
    return value_ % mod;
  }

private:
  value_type value;

public:
  constexpr modular(): value(0) { }
  template <class T>
  explicit constexpr modular(T value_): value(normalize(value_)) { }
  template <class T>
  explicit constexpr operator T() { return static_cast<T>(value); }

  constexpr value_type get() const { return value; }
  constexpr modular operator - () const { return modular(mod - value); }
  constexpr modular operator ~ () const { return inverse(); }

  constexpr value_type &extract() { return value; }
  constexpr modular inverse() const { return power(mod - 2); }
  constexpr modular power(max_type exp) const {
    modular res(1), mult(*this);
    while (exp > 0) {
      if (exp & 1) res *= mult;
      mult *= mult;
      exp >>= 1;
    }
    return res;
  }

  constexpr modular operator + (const modular &rhs) const { return modular(*this) += rhs; }
  constexpr modular& operator += (const modular &rhs) { 
    if ((value += rhs.value) >= mod) value -= mod; 
    return *this; 
  }

  constexpr modular operator - (const modular &rhs) const { return modular(*this) -= rhs; }
  constexpr modular& operator -= (const modular &rhs) { 
    if ((value += mod - rhs.value) >= mod) value -= mod; 
    return *this; 
  }

  constexpr modular operator * (const modular &rhs) const { return modular(*this) *= rhs; }
  constexpr modular& operator *= (const modular &rhs) { 
    value = (max_type) value * rhs.value % mod;
    return *this;
  }

  constexpr modular operator / (const modular &rhs) const { return modular(*this) /= rhs; }
  constexpr modular& operator /= (const modular &rhs) { return (*this) *= rhs.inverse(); }

  constexpr bool zero() const { return value == 0; }
  constexpr bool operator == (const modular &rhs) const { return value == rhs.value; }
  constexpr bool operator != (const modular &rhs) const { return value != rhs.value; }
  friend std::ostream& operator << (std::ostream &stream, const modular &rhs) {
    return stream << rhs.value;
  }

};

using m32 = modular<1000000007>;

using i32 = int32_t;
using i64 = int64_t;
using u32 = uint32_t;
using u64 = uint64_t;

constexpr i32 inf32 = (i32(1) << 30) - 1;
constexpr i64 inf64 = (i64(1) << 62) - 1;

template <class Func>
struct fix_point: private Func {
  explicit constexpr fix_point(Func &&func): Func(std::forward<Func>(func)) { }
  template <class... Args>
  constexpr decltype(auto) operator () (Args &&... args) const {
    return Func::operator()(*this, std::forward<Args>(args)...);
  }
};

int main() {
  size_t N;
  std::cin >> N;
  std::vector<std::vector<i32>> graph(N);
  std::vector<i32> degree(N);
  for (auto i: range(1, N)) {
    i32 x, y;
    std::cin >> x >> y;
    --x; --y;
    graph[x].push_back(y);
    ++degree[y];
  }
  i32 root = -1;
  for (auto i: range(0, N)) {
    if (degree[i] == 0) {
      root = i;
      break;
    }
  }
  std::vector<i32> size(N);
  std::vector<m32> ans(N);
  fix_point([&](auto dfs, i32 u) -> void {
    size[u] = 1;
    for (auto v: graph[u]) {
      dfs(v);
      size[u] += size[v];
      ans[u] += ans[v] + m32(size[v]);
    }
  })(root);
  std::cout << std::accumulate(ans.begin(), ans.end(), m32(0)) << '\n';
  return 0;
}
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