#613912 (C++17) No.1378 Flattening

• 問題: No.1378 Flattening
• ユーザー: risujiroh
• 提出日時: 2021-02-05 22:46:17
• 言語: C++17 (gcc 12.3.0 + boost 1.83.0)
• 結果: AC
• 実行時間: 50 ms / 2,000 ms
• コード長: 4,011 bytes
• コンパイル時間: 2,099 ms
• コンパイル使用メモリ: 207,112 KB
• 実行使用メモリ: 5,376 KB
• 最終ジャッジ日時: 2024-07-02 13:35:27
• 合計ジャッジ時間: 3,842 ms
• ジャッジサーバーID （参考情報）: judge1 / judge5

入力	結果	実行時間; 実行使用メモリ
testcase_00	AC	2 ms; 5,248 KB
testcase_01	AC	2 ms; 5,376 KB
testcase_02	AC	2 ms; 5,376 KB
testcase_03	AC	2 ms; 5,376 KB
testcase_04	AC	2 ms; 5,376 KB
testcase_05	AC	2 ms; 5,376 KB
testcase_06	AC	2 ms; 5,376 KB
testcase_07	AC	2 ms; 5,376 KB
testcase_08	AC	2 ms; 5,376 KB
testcase_09	AC	2 ms; 5,376 KB
testcase_10	AC	2 ms; 5,376 KB
testcase_11	AC	2 ms; 5,376 KB
testcase_12	AC	2 ms; 5,376 KB
testcase_13	AC	2 ms; 5,376 KB
testcase_14	AC	2 ms; 5,376 KB
testcase_15	AC	2 ms; 5,376 KB
testcase_16	AC	2 ms; 5,376 KB
testcase_17	AC	2 ms; 5,376 KB
testcase_18	AC	2 ms; 5,376 KB
testcase_19	AC	2 ms; 5,376 KB
testcase_20	AC	2 ms; 5,376 KB
testcase_21	AC	2 ms; 5,376 KB
testcase_22	AC	2 ms; 5,376 KB
testcase_23	AC	2 ms; 5,376 KB
testcase_24	AC	2 ms; 5,376 KB
testcase_25	AC	2 ms; 5,376 KB
testcase_26	AC	2 ms; 5,376 KB
testcase_27	AC	2 ms; 5,376 KB
testcase_28	AC	2 ms; 5,376 KB
testcase_29	AC	2 ms; 5,376 KB
testcase_30	AC	2 ms; 5,376 KB
testcase_31	AC	50 ms; 5,376 KB
testcase_32	AC	50 ms; 5,376 KB
testcase_33	AC	32 ms; 5,376 KB
testcase_34	AC	33 ms; 5,376 KB
testcase_35	AC	49 ms; 5,376 KB
testcase_36	AC	31 ms; 5,376 KB
testcase_37	AC	14 ms; 5,376 KB
testcase_38	AC	14 ms; 5,376 KB
testcase_39	AC	14 ms; 5,376 KB
testcase_40	AC	13 ms; 5,376 KB
testcase_41	AC	14 ms; 5,376 KB
testcase_42	AC	13 ms; 5,376 KB
testcase_43	AC	14 ms; 5,376 KB
testcase_44	AC	14 ms; 5,376 KB
testcase_45	AC	3 ms; 5,376 KB
testcase_46	AC	4 ms; 5,376 KB
testcase_47	AC	2 ms; 5,376 KB
testcase_48	AC	11 ms; 5,376 KB
testcase_49	AC	13 ms; 5,376 KB
testcase_50	AC	2 ms; 5,376 KB
testcase_51	AC	2 ms; 5,376 KB

ソースコード

#include <bits/stdc++.h>

template <uint32_t Modulus>
class ModularInt {
  using M = ModularInt;

 public:
  static_assert(int(Modulus) >= 1, "Modulus must be in the range [1, 2^31)");
  static constexpr int modulus() { return Modulus; }
  static M raw(uint32_t v) { return *reinterpret_cast<M*>(&v); }

  ModularInt() : v_(0) {}
  ModularInt(int64_t v) : v_((v %= Modulus) < 0 ? v + Modulus : v) {}

  template <class T>
  explicit operator T() const {
    return v_;
  }
  M& operator++() { return v_ = ++v_ == Modulus ? 0 : v_, *this; }
  M& operator--() { return --(v_ ? v_ : v_ = Modulus), *this; }
  M operator+() const { return *this; }
  M operator-() const { return raw(v_ ? Modulus - v_ : 0); }
  M& operator*=(M o) { return v_ = uint64_t(v_) * o.v_ % Modulus, *this; }
  M& operator/=(M o) {
    auto [inv, gcd] = extgcd(o.v_, Modulus);
    assert(gcd == 1);
    return *this *= inv;
  }
  M& operator+=(M o) {
    return v_ = int(v_ += o.v_ - Modulus) < 0 ? v_ + Modulus : v_, *this;
  }
  M& operator-=(M o) {
    return v_ = int(v_ -= o.v_) < 0 ? v_ + Modulus : v_, *this;
  }

  friend M operator++(M& a, int) { return std::exchange(a, ++M(a)); }
  friend M operator--(M& a, int) { return std::exchange(a, --M(a)); }
  friend M operator*(M a, M b) { return a *= b; }
  friend M operator/(M a, M b) { return a /= b; }
  friend M operator+(M a, M b) { return a += b; }
  friend M operator-(M a, M b) { return a -= b; }
  friend std::istream& operator>>(std::istream& is, M& x) {
    int64_t v;
    return is >> v, x = v, is;
  }
  friend std::ostream& operator<<(std::ostream& os, M x) { return os << x.v_; }
  friend bool operator==(M a, M b) { return a.v_ == b.v_; }
  friend bool operator!=(M a, M b) { return a.v_ != b.v_; }

 private:
  static std::array<int, 2> extgcd(int a, int b) {
    std::array x{1, 0};
    while (b) std::swap(x[0] -= a / b * x[1], x[1]), std::swap(a %= b, b);
    return {x[0], a};
  }

  uint32_t v_;
};

#pragma region my_template

struct Rep {
  struct I {
    int i;
    void operator++() { ++i; }
    int operator*() const { return i; }
    bool operator!=(I o) const { return i < *o; }
  };
  const int l_, r_;
  Rep(int l, int r) : l_(l), r_(r) {}
  Rep(int n) : Rep(0, n) {}
  I begin() const { return {l_}; }
  I end() const { return {r_}; }
};
struct Per {
  struct I {
    int i;
    void operator++() { --i; }
    int operator*() const { return i; }
    bool operator!=(I o) const { return i > *o; }
  };
  const int l_, r_;
  Per(int l, int r) : l_(l), r_(r) {}
  Per(int n) : Per(0, n) {}
  I begin() const { return {r_ - 1}; }
  I end() const { return {l_ - 1}; }
};

template <class F>
struct Fix : private F {
  Fix(F f) : F(f) {}
  template <class... Args>
  decltype(auto) operator()(Args&&... args) const {
    return F::operator()(*this, std::forward<Args>(args)...);
  }
};

template <class T = int>
T scan() {
  T res;
  std::cin >> res;
  return res;
}

template <class T, class U = T>
bool chmin(T& a, U&& b) {
  return b < a ? a = std::forward<U>(b), true : false;
}
template <class T, class U = T>
bool chmax(T& a, U&& b) {
  return a < b ? a = std::forward<U>(b), true : false;
}

#ifndef LOCAL
#define DUMP(...) void(0)
template <int OnlineJudge, int Local>
constexpr int OjLocal = OnlineJudge;
#endif

using namespace std;

#define ALL(c) begin(c), end(c)

#pragma endregion

using Mint = ModularInt<998244353>;

int main() {
  cin.tie(nullptr)->sync_with_stdio(false);
  cout << fixed << setprecision(20);
  int n = scan();
  vector<int> a(n);
  generate(ALL(a), scan<>);

  vector<Mint> f(n + 1);
  f[0] = 1;

  for (int pos : Rep(n)) {
    auto nf = f;
    int l = pos, r = pos;
    while (l and a[l - 1] >= a[pos]) --l;
    while (r < n and a[r] >= a[pos]) ++r;
    for (int i : Rep(l, r))
      if (a[i] >= a[pos]) nf[i + 1] += nf[i];
    f = move(nf);
  }

  cout << f[n] << '\n';
}