#499218 (C++17) No.1084 積の積

• 問題: No.1084 積の積
• ユーザー: KoD
• 提出日時: 2020-06-19 22:05:29
• 言語: C++17 (gcc 12.3.0 + boost 1.83.0)
• 結果: AC
• 実行時間: 69 ms / 2,000 ms
• コード長: 5,044 bytes
• コンパイル時間: 696 ms
• コンパイル使用メモリ: 81,732 KB
• 実行使用メモリ: 6,948 KB
• 最終ジャッジ日時: 2024-07-03 14:46:23
• 合計ジャッジ時間: 2,709 ms
• ジャッジサーバーID （参考情報）: judge2 / judge1

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; 6,944 KB
testcase_02	AC	2 ms; 6,940 KB
testcase_03	AC	2 ms; 6,944 KB
testcase_04	AC	52 ms; 6,944 KB
testcase_05	AC	3 ms; 6,944 KB
testcase_06	AC	53 ms; 6,940 KB
testcase_07	AC	2 ms; 6,940 KB
testcase_08	AC	2 ms; 6,940 KB
testcase_09	AC	22 ms; 6,944 KB
testcase_10	AC	1 ms; 6,944 KB
testcase_11	AC	4 ms; 6,940 KB
testcase_12	AC	29 ms; 6,940 KB
testcase_13	AC	59 ms; 6,944 KB
testcase_14	AC	23 ms; 6,944 KB
testcase_15	AC	21 ms; 6,940 KB
testcase_16	AC	69 ms; 6,940 KB
testcase_17	AC	27 ms; 6,940 KB
testcase_18	AC	46 ms; 6,948 KB
testcase_19	AC	62 ms; 6,940 KB
testcase_20	AC	15 ms; 6,944 KB
testcase_21	AC	24 ms; 6,944 KB
testcase_22	AC	18 ms; 6,944 KB
testcase_23	AC	37 ms; 6,944 KB
testcase_24	AC	34 ms; 6,944 KB
testcase_25	AC	59 ms; 6,944 KB
testcase_26	AC	51 ms; 6,940 KB
testcase_27	AC	51 ms; 6,944 KB
testcase_28	AC	51 ms; 6,944 KB
testcase_29	AC	51 ms; 6,940 KB
testcase_30	AC	50 ms; 6,940 KB
testcase_31	AC	51 ms; 6,940 KB

ソースコード

#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;

int main() {
  size_t N;
  std::cin >> N;
  std::vector<u64> A(N);
  for (auto &x: A) {
    std::cin >> x;
    if (x == 0) {
      std::cout << "0\n";
      return 0;
    }
  }
  std::vector<size_t> right(N);
  {
    size_t r = 0;
    u64 cur = 1;
    for (auto l: range(0, N)) {
      while (r < N && cur * A[r] < 1000000000) {
        cur *= A[r];
        ++r;
      }
      right[l] = r;
      cur /= A[l];
    }
  }
  std::vector<m32> p(N + 1);
  p.front() = (m32) 1;
  for (auto i: range(0, N)) {
    p[i + 1] = p[i] * (m32) A[i];
  }
  std::vector<m32> p2(N + 1);
  p2.front() = (m32) 1;
  for (auto i: range(0, N)) {
    p2[i + 1] = p2[i] * (m32) p[i + 1];
  }
  m32 ans(1);
  for (auto i: range(0, N)) {
    ans *= p2[right[i]] / p[i].power(right[i] - i) / p2[i];
  }
  std::cout << ans << '\n';
  return 0;
}