cp-library-cpp

This documentation is automatically generated by online-judge-tools/verification-helper

View the Project on GitHub naskya/cp-library-cpp

:heavy_check_mark: test/data_structure/binary_indexed_tree/1.test.cpp

Depends on

Code

#define PROBLEM "https://yukicoder.me/problems/no/1300"
#include <algorithm>
#include <iostream>
#include <iterator>
#include <map>

#include "../../../include/algebra/static_modint.hpp"
#include "../../../include/data_structure/binary_indexed_tree.hpp"

int main() {
  std::ios_base::sync_with_stdio(false);
  std::cin.tie(nullptr);

  int N;
  std::cin >> N;

  std::vector<int> A(N);
  std::copy_n(std::istream_iterator<int>(std::cin), N, std::begin(A));

  std::map<int, int> count;
  std::for_each(std::cbegin(A), std::cend(A), [&](const int a) { ++count[a]; });

  std::vector<std::pair<int, int>> L, R;
  std::for_each(std::cbegin(count), std::cend(count), [&](const auto p) { L.emplace_back(p); R.emplace_back(p); });

  std::sort(std::begin(L), std::end(L));
  std::sort(std::rbegin(R), std::rend(R));

  const int M = static_cast<int>(std::size(L));

  lib::binary_indexed_tree<long long> L_acc(M), R_acc(M);
  lib::binary_indexed_tree<int> L_cnt(M), R_cnt(M);

  for (int i = 0; i < M; i++) {
    L_acc.add(i, L[i].first * L[i].second);
    L_cnt.add(i, L[i].second);
    R_acc.add(i, R[i].first * R[i].second);
    R_cnt.add(i, R[i].second);
  }

  using mint = lib::static_modint<998244353>;

  std::vector<mint> right(N), left(N);
  std::vector<int> rs(N), ls(N);

  for (int i = 0; i < N - 1; i++) {
    const int idx = static_cast<int>(std::distance(std::cbegin(L), std::lower_bound(std::cbegin(L), std::cend(L), std::pair {A[i], 0})));
    L_cnt.add(idx, -1);
    L_acc.add(idx, -A[i]);

    if (i == 0 || idx == 0)
      continue;

    right[i] = mint(L_acc.sum(0, idx));
    rs[i]    = L_cnt.sum(0, idx);
  }

  for (int i = 0; i < N - 1; i++) {
    const int idx = static_cast<int>(std::distance(std::lower_bound(std::crbegin(R), std::crend(R), std::pair {A[N - 1 - i], 0}), std::crend(R)) - 1);
    --R[idx].second;
    R_cnt.add(idx, -1);
    R_acc.add(idx, -A[N - 1 - i]);

    if (i == 0 || idx == 0)
      continue;

    left[i] = mint(R_acc.sum(0, idx));
    ls[i]   = R_cnt.sum(0, idx);
  }

  std::reverse(std::begin(left), std::end(left));
  std::reverse(std::begin(ls), std::end(ls));

  mint res;

  for (int i = 0; i < N - 1; i++) {
    res += mint(right[i]) * ls[i];
    res += mint(left[i]) * rs[i];
    res += mint(A[i]) * rs[i] * ls[i];
  }

  std::cout << res << '\n';
}
#line 1 "test/data_structure/binary_indexed_tree/1.test.cpp"
#define PROBLEM "https://yukicoder.me/problems/no/1300"
#include <algorithm>
#include <iostream>
#include <iterator>
#include <map>

#line 1 "include/algebra/static_modint.hpp"

//! @file static_modint.hpp

#ifndef CP_LIBRARY_STATIC_MODINT_HPP
#define CP_LIBRARY_STATIC_MODINT_HPP

#include <cassert>
#include <cstdint>
#line 10 "include/algebra/static_modint.hpp"
#include <limits>
#include <type_traits>

#define CP_LIBRARY_USE_CONSTEXPR

#ifndef CP_LIBRARY_WARN
#  if (CP_LIBRARY_DEBUG_LEVEL >= 1)
//! @brief Print warning message
//! @note You can suppress the warning by uncommenting the following line
#    define CP_LIBRARY_WARN(msg) (std::cerr << (msg) << '\n')
// #  define CP_LIBRARY_WARN(msg) (static_cast<void>(0))
#  else
#    define CP_LIBRARY_WARN(msg) (static_cast<void>(0))
#    undef CP_LIBRARY_USE_CONSTEXPR
#    define CP_LIBRARY_USE_CONSTEXPR constexpr
#  endif
#  define CP_LIBRARY_WARN_NOT_DEFINED
#endif

#ifndef CP_LIBRARY_ASSERT
//! @brief Assert macro
#  define CP_LIBRARY_ASSERT(...) assert(__VA_ARGS__)
#  define CP_LIBRARY_ASSERT_NOT_DEFINED
#endif

namespace lib {

//! @brief modint (for compile-time constant modulo)
//! @tparam modulo modulo (e.g. 1000000007).
template <std::int_least32_t modulo,
          std::enable_if_t<(1 < modulo) && (modulo < std::numeric_limits<std::int_least32_t>::max() / 2),
                           std::nullptr_t> = nullptr>
struct static_modint {
private:
  std::int_least32_t value;

  //! @param n non-zero integer
  //! @return multiplicative inverse of n
  template <typename Tp>
  [[nodiscard]] static std::int_least32_t calc_inverse(Tp n) {
    CP_LIBRARY_ASSERT(n != 0);

    Tp b = modulo, u = 1, v = 0, t;
    while (b > 0) {
      t = n / b;
      // std::swap is not necessarily constexpr in C++17
      // std::swap(n -= t * b, b);
      Tp tmp = std::move(n -= t * b);
      n      = std::move(b);
      b      = std::move(tmp);
      // std::swap(u -= t * v, v);
      tmp = std::move(u -= t * v);
      u   = std::move(v);
      v   = std::move(tmp);
    }
    if (u < 0)
      u += modulo;
    return static_cast<std::int_least32_t>(u);
  }

  //! @brief Calculate modulo and keep the value within [0, modulo)
  //! @param v integer
  //! @return integer within [0, modulo)
  //! @note Time complexity: O(1)
  template <typename Tp>
  [[nodiscard]] static constexpr std::int_least32_t clamp_ll(Tp v) noexcept {
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wsign-compare"
    if (modulo <= v || v < -modulo)
      v %= modulo;
#pragma GCC diagnostic pop

    if (v < 0)
      v += modulo;
    return static_cast<std::int_least32_t>(v);
  }

  //! @brief Calculate modulo and keep the value within [0, modulo)
  //! @note Time complexity: O(1)
  constexpr void clamp_self() noexcept {
    if (0 <= value) {
      if (value < modulo)
        return;
      if (value < modulo * 2)
        value -= modulo;
      else
        value -= modulo * 2;
    } else {
      if (-modulo < value)
        value += modulo;
      else if (-modulo * 2 < value)
        value += modulo * 2;
      else {
        value += modulo;
        value += modulo * 2;
      }
    }
  }

public:
  //! @brief underlying integer type
  using type = std::int_least32_t;

  //! @return modulo (e.g. 1000000007)
  [[nodiscard]] static constexpr type mod() noexcept {
    return modulo;
  }

  //! @brief Create a modint of value 0
  constexpr static_modint() noexcept : value(0) {}

  //! @brief Create a modint without taking modulo
  constexpr static_modint(const type v, bool) noexcept : value(v) {}

  //! @brief Create a modint
  template <typename ValueType>
  constexpr static_modint(const ValueType v) noexcept : value() {
    if constexpr (std::is_integral_v<ValueType> && (std::numeric_limits<ValueType>::digits <= 32)) {
      value = v;
      clamp_self();
    } else {
      value = clamp_ll(v);
    }
  }

  [[nodiscard]] constexpr static_modint operator+(const static_modint rhs) const noexcept {
    return static_modint(value + rhs.value);
  }
  [[nodiscard]] constexpr static_modint operator-(const static_modint rhs) const noexcept {
    return static_modint(value - rhs.value);
  }
  [[nodiscard]] constexpr static_modint operator*(const static_modint rhs) const noexcept {
    return static_modint(static_cast<std::int_least64_t>(value) * rhs.value);
  }
  [[nodiscard]] static_modint operator/(const static_modint rhs) const {
    return static_modint(static_cast<std::int_least64_t>(value) * calc_inverse(rhs.value));
  }

  [[nodiscard]] CP_LIBRARY_USE_CONSTEXPR static_modint operator%(const static_modint rhs) const {
    CP_LIBRARY_WARN("static_modint::operator% : Are you sure you want to do this?");
    return static_modint(value % rhs.value);
  }

  [[nodiscard]] CP_LIBRARY_USE_CONSTEXPR static_modint operator&(const static_modint rhs) const {
    CP_LIBRARY_WARN("static_modint::operator& : Are you sure you want to do this?");
    return static_modint(value & rhs.value, true);
  }
  [[nodiscard]] CP_LIBRARY_USE_CONSTEXPR static_modint operator|(const static_modint rhs) const {
    CP_LIBRARY_WARN("static_modint::operator| : Are you sure you want to do this?");
    return static_modint(value | rhs.value);
  }
  [[nodiscard]] CP_LIBRARY_USE_CONSTEXPR static_modint operator^(const static_modint rhs) const {
    CP_LIBRARY_WARN("static_modint::operator^ : Are you sure you want to do this?");
    return static_modint(value ^ rhs.value);
  }
  [[nodiscard]] CP_LIBRARY_USE_CONSTEXPR static_modint operator<<(const static_modint rhs) const {
    CP_LIBRARY_WARN("static_modint::operator<< : Are you sure you want to do this?");
    return static_modint(static_cast<std::int_least64_t>(value) << rhs.value);
  }
  [[nodiscard]] CP_LIBRARY_USE_CONSTEXPR static_modint operator>>(const static_modint rhs) const {
    CP_LIBRARY_WARN("static_modint::operator>> : Are you sure you want to do this?");
    return static_modint(value >> rhs.value, true);
  }

  constexpr static_modint& operator+=(const static_modint rhs) noexcept {
    value += rhs.value;
    if (value >= modulo)
      value -= modulo;
    return *this;
  }
  constexpr static_modint& operator-=(const static_modint rhs) noexcept {
    value -= rhs.value;
    if (value < 0)
      value += modulo;
    return *this;
  }
  constexpr static_modint& operator*=(const static_modint rhs) noexcept {
    value = clamp_ll(static_cast<std::int_least64_t>(value) * rhs.value);
    return *this;
  }
  static_modint& operator/=(const static_modint rhs) {
    value = clamp_ll(static_cast<std::int_least64_t>(value) * calc_inverse(rhs.value));
    return *this;
  }

  CP_LIBRARY_USE_CONSTEXPR static_modint& operator%=(const static_modint rhs) {
    CP_LIBRARY_WARN("static_modint::operator%= : Are you sure you want to do this?");
    value %= rhs.value;
    if (value < 0)
      value += modulo;
    return *this;
  }

  CP_LIBRARY_USE_CONSTEXPR static_modint& operator&=(const static_modint rhs) {
    CP_LIBRARY_WARN("static_modint::operator&= : Are you sure you want to do this?");
    value &= rhs.value;
    return *this;
  }
  CP_LIBRARY_USE_CONSTEXPR static_modint& operator|=(const static_modint rhs) {
    CP_LIBRARY_WARN("static_modint::operator|= : Are you sure you want to do this?");
    value |= rhs.value;
    clamp_self();
    return *this;
  }
  CP_LIBRARY_USE_CONSTEXPR static_modint& operator^=(const static_modint rhs) {
    CP_LIBRARY_WARN("static_modint::operator^= : Are you sure you want to do this?");
    value ^= rhs.value;
    clamp_self();
    return *this;
  }
  CP_LIBRARY_USE_CONSTEXPR static_modint& operator<<=(const static_modint rhs) {
    CP_LIBRARY_WARN("operator<<= : Are you sure you want to do this?");
    value = clamp_ll(static_cast<std::int_least64_t>(value) << rhs.value);
    return *this;
  }
  CP_LIBRARY_USE_CONSTEXPR static_modint& operator>>=(const static_modint rhs) {
    CP_LIBRARY_WARN("operator>>= : Are you sure you want to do this?");
    value >>= rhs.value;
    return *this;
  }

  template <typename RhsType>
  [[nodiscard]] constexpr static_modint operator+(const RhsType rhs) const noexcept {
    return static_modint(value + clamp_ll(rhs));
  }
  template <typename RhsType>
  [[nodiscard]] constexpr static_modint operator-(const RhsType rhs) const noexcept {
    return static_modint(value - clamp_ll(rhs));
  }
  template <typename RhsType>
  [[nodiscard]] constexpr static_modint operator*(const RhsType rhs) const noexcept {
    return static_modint(static_cast<std::int_least64_t>(value) * clamp_ll(rhs));
  }
  template <typename RhsType>
  [[nodiscard]] static_modint operator/(const RhsType rhs) const {
    std::int_least64_t mul = (rhs > 0) ? calc_inverse(rhs) : -calc_inverse(-rhs);
    return static_modint(value * mul);
  }

  template <typename RhsType>
  [[nodiscard]] CP_LIBRARY_USE_CONSTEXPR static_modint operator%(const RhsType rhs) const {
    CP_LIBRARY_WARN("static_modint::operator% : Are you sure you want to do this?");
    return static_modint(value % rhs, true);
  }

  template <typename RhsType>
  [[nodiscard]] CP_LIBRARY_USE_CONSTEXPR static_modint operator&(const RhsType rhs) const {
    CP_LIBRARY_WARN("static_modint::operator& : Are you sure you want to do this?");
    return static_modint(value & rhs, true);
  }
  template <typename RhsType>
  [[nodiscard]] CP_LIBRARY_USE_CONSTEXPR static_modint operator|(const RhsType rhs) const {
    CP_LIBRARY_WARN("static_modint::operator| : Are you sure you want to do this?");
    return static_modint(value | rhs);
  }
  template <typename RhsType>
  [[nodiscard]] CP_LIBRARY_USE_CONSTEXPR static_modint operator^(const RhsType rhs) const {
    CP_LIBRARY_WARN("static_modint::operator^ : Are you sure you want to do this?");
    return static_modint(value ^ rhs);
  }
  template <typename RhsType>
  [[nodiscard]] CP_LIBRARY_USE_CONSTEXPR static_modint operator<<(const RhsType rhs) const {
    CP_LIBRARY_WARN("static_modint::operator<< : Are you sure you want to do this?");
    return static_modint(static_cast<std::int_least64_t>(value) << rhs);
  }
  template <typename RhsType>
  [[nodiscard]] CP_LIBRARY_USE_CONSTEXPR static_modint operator>>(const RhsType rhs) const {
    CP_LIBRARY_WARN("static_modint::operator>> : Are you sure you want to do this?");
    return static_modint(value >> rhs, true);
  }

  template <typename RhsType>
  constexpr static_modint& operator+=(const RhsType rhs) noexcept {
    value = clamp_ll(static_cast<std::int_least64_t>(value) + rhs);
    return *this;
  }
  template <typename RhsType>
  constexpr static_modint& operator-=(const RhsType rhs) noexcept {
    value = clamp_ll(static_cast<std::int_least64_t>(value) - rhs);
    return *this;
  }
  template <typename RhsType>
  constexpr static_modint& operator*=(const RhsType rhs) noexcept {
    value = clamp_ll(static_cast<std::int_least64_t>(value) * clamp_ll(rhs));
    return *this;
  }
  template <typename RhsType>
  static_modint& operator/=(const RhsType rhs) {
    std::int_least64_t mul = (rhs > 0) ? calc_inverse(rhs) : -calc_inverse(-rhs);
    value = clamp_ll(value * mul);
    return *this;
  }

  template <typename RhsType>
  CP_LIBRARY_USE_CONSTEXPR static_modint& operator%=(const RhsType rhs) {
    CP_LIBRARY_WARN("static_modint::operator%= : Are you sure you want to do this?");
    value %= rhs;
    return *this;
  }

  template <typename RhsType>
  CP_LIBRARY_USE_CONSTEXPR static_modint& operator&=(const RhsType rhs) {
    CP_LIBRARY_WARN("static_modint::operator&= : Are you sure you want to do this?");
    value &= rhs;
    return *this;
  }
  template <typename RhsType>
  CP_LIBRARY_USE_CONSTEXPR static_modint& operator|=(const RhsType rhs) {
    CP_LIBRARY_WARN("static_modint::operator|= : Are you sure you want to do this?");
    value |= rhs;
    clamp_self();
    return *this;
  }
  template <typename RhsType>
  CP_LIBRARY_USE_CONSTEXPR static_modint& operator^=(const RhsType rhs) {
    CP_LIBRARY_WARN("static_modint::operator^= : Are you sure you want to do this?");
    value ^= rhs;
    clamp_self();
    return *this;
  }
  template <typename RhsType>
  CP_LIBRARY_USE_CONSTEXPR static_modint& operator<<=(const RhsType rhs) {
    CP_LIBRARY_WARN("operator<<= : Are you sure you want to do this?");
    value = clamp_ll(static_cast<std::int_least64_t>(value) << rhs);
    return *this;
  }
  template <typename RhsType>
  CP_LIBRARY_USE_CONSTEXPR static_modint& operator>>=(const RhsType rhs) {
    CP_LIBRARY_WARN("operator>>= : Are you sure you want to do this?");
    value >>= rhs;
    return *this;
  }

  [[nodiscard]] CP_LIBRARY_USE_CONSTEXPR bool operator!() const {
    CP_LIBRARY_WARN("static_modint::operator! : Are you sure you want to do this?");
    return value == 0;
  }
  [[nodiscard]] CP_LIBRARY_USE_CONSTEXPR static_modint operator~() const {
    CP_LIBRARY_WARN("static_modint::operator~ : Are you sure you want to do this?");
    return static_modint(~value);
  }
  [[nodiscard]] constexpr static_modint operator-() const noexcept {
    return static_modint(value == 0 ? 0 : modulo - value, true);
  }
  [[nodiscard]] constexpr static_modint& operator+() const noexcept {
    return *this;
  }

  constexpr static_modint& operator++() noexcept {
    value = ((value + 1 == modulo) ? 0 : value + 1);
    return *this;
  }
  constexpr static_modint& operator--() noexcept {
    value = ((value == 0) ? modulo - 1 : value - 1);
    return *this;
  }
  constexpr static_modint operator++(int) noexcept {
    std::int_least32_t res = value;
    ++(*this);
    return static_modint(res, true);
  }
  constexpr static_modint operator--(int) noexcept {
    std::int_least32_t res = value;
    --(*this);
    return static_modint(res, true);
  }

  [[nodiscard]] constexpr bool operator==(const static_modint rhs) const noexcept {
    return value == rhs.value;
  }
  [[nodiscard]] constexpr bool operator!=(const static_modint rhs) const noexcept {
    return value != rhs.value;
  }
  [[nodiscard]] CP_LIBRARY_USE_CONSTEXPR bool operator<(const static_modint rhs) const {
    CP_LIBRARY_WARN("static_modint::operator< : Are you sure you want to do this?");
    return value < rhs.value;
  }
  [[nodiscard]] CP_LIBRARY_USE_CONSTEXPR bool operator<=(const static_modint rhs) const {
    CP_LIBRARY_WARN("static_modint::operator<= : Are you sure you want to do this?");
    return value <= rhs.value;
  }
  [[nodiscard]] CP_LIBRARY_USE_CONSTEXPR bool operator>(const static_modint rhs) const {
    CP_LIBRARY_WARN("static_modint::operator> : Are you sure you want to do this?");
    return value > rhs.value;
  }
  [[nodiscard]] CP_LIBRARY_USE_CONSTEXPR bool operator>=(const static_modint rhs) const {
    CP_LIBRARY_WARN("static_modint::operator>= : Are you sure you want to do this?");
    return value >= rhs.value;
  }

  template <typename RhsType>
  [[nodiscard]] constexpr bool operator==(const RhsType rhs) const noexcept {
    return value == rhs;
  }
  template <typename RhsType>
  [[nodiscard]] constexpr bool operator!=(const RhsType rhs) const noexcept {
    return value != rhs;
  }
  template <typename RhsType>
  [[nodiscard]] CP_LIBRARY_USE_CONSTEXPR bool operator<(const RhsType rhs) const {
    CP_LIBRARY_WARN("static_modint::operator< : Are you sure you want to do this?");
    return value < rhs;
  }
  template <typename RhsType>
  [[nodiscard]] CP_LIBRARY_USE_CONSTEXPR bool operator<=(const RhsType rhs) const {
    CP_LIBRARY_WARN("static_modint::operator<= : Are you sure you want to do this?");
    return value <= rhs;
  }
  template <typename RhsType>
  [[nodiscard]] CP_LIBRARY_USE_CONSTEXPR bool operator>(const RhsType rhs) const {
    CP_LIBRARY_WARN("static_modint::operator> : Are you sure you want to do this?");
    return value > rhs;
  }
  template <typename RhsType>
  [[nodiscard]] CP_LIBRARY_USE_CONSTEXPR bool operator>=(const RhsType rhs) const {
    CP_LIBRARY_WARN("static_modint::operator>= : Are you sure you want to do this?");
    return value >= rhs;
  }

  [[nodiscard]] constexpr operator std::int_least32_t() const {
    CP_LIBRARY_WARN("A value of type static_modint has been cast to type std::int_lease32_t.");
    return value;
  }

  //! @brief Read value (64-bit signed integer) from std::istream& is, take modulo, and store it in rhs.
  //! @return std::istream& is
  friend std::istream& operator>>(std::istream& is, static_modint& rhs) {
    std::int_least64_t tmp;
    is >> tmp;
    if (tmp < -modulo || modulo <= tmp)
      tmp %= modulo;
    if (tmp < 0)
      tmp += modulo;
    rhs.value = static_cast<std::int_least32_t>(tmp);
    return is;
  }
  //! @brief Print value to std::ostream& os
  //! @return std::ostream& os
  friend std::ostream& operator<<(std::ostream& os, static_modint& rhs) {
    return os << rhs.value;
  }

  //! @return multiplicative inverse
  [[nodiscard]] static_modint inv() const {
    return static_modint(calc_inverse(value), true);
  }
  //! @tparam index_positive_guaranteed set true if and only if you can promise that index is positive
  //! @tparam Tp integer type (deduced from parameter)
  //! @param index index. This must be an integer, but doesn't have to be primitive.
  //! @return index-th power of the value
  //! @note Time complexity: O(log(index))
  template <bool index_positive_guaranteed = true, typename Tp = std::int_least32_t>
  [[nodiscard]] static_modint pow(Tp index) const noexcept {
    if constexpr (!index_positive_guaranteed) {
      if (value == 0)
        return static_modint(0, true);
      if (index == 0)
        return static_modint(1, true);
      if (index < 0)
        return static_modint(value, true).inv().pow<true>(-index);
    }
    static_modint res(1, true), base(value, true);
    while (index > 0) {
      if ((index & 1) == 1)
        res *= base;
      base *= base;
      index >>= 1;
    }
    return res;
  }
  //! @return a pair (a, b) such that b > 0, value is equal to a * (mult inverse of b), and (a + b) is minimal
  [[nodiscard]] constexpr std::pair<std::int_least32_t, std::int_least32_t> to_frac() const noexcept {
    std::int_least32_t x = modulo - value, y = value, u = 1, v = 1;
    std::pair<std::int_least32_t, std::int_least32_t> res {value, 1};

    std::int_least32_t num = value, den = 1;
    std::int_least32_t cost = num + den;

    while (x > 0) {
      if (x <= num) {
        std::int_least32_t q = num / x;
        num                  = num % x;
        den += q * u;
        if (num == 0)
          break;
        if (num + den < cost) {
          cost       = num + den;
          res.first  = num;
          res.second = den;
        }
      }
      std::int_least32_t q = y / x;
      y                    = y % x;
      v += q * u;
      q = x / y;
      x = x % y;
      u += q * v;
    }

    return res;
  }
};

template <typename LhsType, std::int_least32_t modulo>
[[nodiscard]] constexpr static_modint<modulo> operator+(const LhsType lhs, const static_modint<modulo> rhs) noexcept {
  return rhs + lhs;
}
template <typename LhsType, std::int_least32_t modulo>
[[nodiscard]] constexpr static_modint<modulo> operator-(const LhsType lhs, const static_modint<modulo> rhs) noexcept {
  return -rhs + lhs;
}
template <typename LhsType, std::int_least32_t modulo>
[[nodiscard]] constexpr static_modint<modulo> operator*(const LhsType lhs, const static_modint<modulo> rhs) noexcept {
  return rhs * lhs;
}
template <typename LhsType, std::int_least32_t modulo>
[[nodiscard]] static_modint<modulo> operator/(const LhsType lhs, const static_modint<modulo> rhs) {
  return rhs.inv() * lhs;
}

template <typename LhsType, std::int_least32_t modulo>
[[nodiscard]] CP_LIBRARY_USE_CONSTEXPR static_modint<modulo>
operator%(const LhsType lhs, const static_modint<modulo> rhs) {
  CP_LIBRARY_WARN("static_modint::operator% : Are you sure you want to do this?");
  return static_modint<modulo>(lhs % static_cast<std::int_least32_t>(rhs), true);
}

template <typename LhsType, std::int_least32_t modulo, std::enable_if_t<std::is_integral_v<LhsType>, std::nullptr_t> = nullptr>
[[nodiscard]] CP_LIBRARY_USE_CONSTEXPR static_modint<modulo>
operator<<(const LhsType lhs, const static_modint<modulo> rhs) {
  CP_LIBRARY_WARN("static_modint::operator<< : Are you sure you want to do this?");
  return static_modint<modulo>(static_cast<std::int_least64_t>(lhs) << static_cast<std::int_least32_t>(rhs));
}
template <typename LhsType, std::int_least32_t modulo, std::enable_if_t<std::is_integral_v<LhsType>, std::nullptr_t> = nullptr>
[[nodiscard]] CP_LIBRARY_USE_CONSTEXPR static_modint<modulo>
operator>>(const LhsType lhs, const static_modint<modulo> rhs) {
  CP_LIBRARY_WARN("static_modint::operator>> : Are you sure you want to do this?");
  return static_modint<modulo>(lhs >> static_cast<std::int_least32_t>(rhs));
}

template <typename LhsType, std::int_least32_t modulo>
constexpr LhsType& operator+=(LhsType& lhs, const static_modint<modulo> rhs) noexcept {
  return lhs += static_cast<std::int_least32_t>(rhs);
}
template <typename LhsType, std::int_least32_t modulo>
constexpr LhsType& operator-=(LhsType& lhs, const static_modint<modulo> rhs) noexcept {
  return lhs -= static_cast<std::int_least32_t>(rhs);
}
template <typename LhsType, std::int_least32_t modulo>
constexpr LhsType& operator*=(LhsType& lhs, const static_modint<modulo> rhs) noexcept {
  return lhs *= static_cast<std::int_least32_t>(rhs);
}
template <typename LhsType, std::int_least32_t modulo>
constexpr LhsType& operator/=(LhsType& lhs, const static_modint<modulo> rhs) {
  return lhs /= static_cast<std::int_least32_t>(rhs);
}

template <typename LhsType, std::int_least32_t modulo>
CP_LIBRARY_USE_CONSTEXPR LhsType& operator%=(LhsType& lhs, const static_modint<modulo> rhs) {
  CP_LIBRARY_WARN("static_modint::operator%= : Are you sure you want to do this?");
  return lhs %= static_cast<std::int_least32_t>(rhs);
}

template <typename LhsType, std::int_least32_t modulo>
CP_LIBRARY_USE_CONSTEXPR LhsType& operator&=(LhsType& lhs, const static_modint<modulo> rhs) {
  CP_LIBRARY_WARN("static_modint::operator&= : Are you sure you want to do this?");
  return lhs &= static_cast<std::int_least32_t>(rhs);
}
template <typename LhsType, std::int_least32_t modulo>
CP_LIBRARY_USE_CONSTEXPR LhsType& operator|=(LhsType& lhs, const static_modint<modulo> rhs) {
  CP_LIBRARY_WARN("static_modint::operator|= : Are you sure you want to do this?");
  return lhs |= static_cast<std::int_least32_t>(rhs);
}
template <typename LhsType, std::int_least32_t modulo>
CP_LIBRARY_USE_CONSTEXPR LhsType& operator^=(LhsType& lhs, const static_modint<modulo> rhs) {
  CP_LIBRARY_WARN("static_modint::operator^= : Are you sure you want to do this?");
  return lhs ^= static_cast<std::int_least32_t>(rhs);
}
template <typename LhsType, std::int_least32_t modulo>
CP_LIBRARY_USE_CONSTEXPR LhsType& operator<<=(LhsType& lhs, const static_modint<modulo> rhs) {
  CP_LIBRARY_WARN("operator<<= : Are you sure you want to do this?");
  return lhs <<= static_cast<std::int_least32_t>(rhs);
}
template <typename LhsType, std::int_least32_t modulo>
CP_LIBRARY_USE_CONSTEXPR LhsType& operator>>=(LhsType& lhs, const static_modint<modulo> rhs) {
  CP_LIBRARY_WARN("operator>>= : Are you sure you want to do this?");
  return lhs >>= static_cast<std::int_least32_t>(rhs);
}

template <typename LhsType, std::int_least32_t modulo>
[[nodiscard]] CP_LIBRARY_USE_CONSTEXPR bool operator<(const LhsType lhs, const static_modint<modulo> rhs) {
  CP_LIBRARY_WARN("static_modint::operator< : Are you sure you want to do this?");
  return lhs < static_cast<std::int_least32_t>(rhs);
}
template <typename LhsType, std::int_least32_t modulo>
[[nodiscard]] CP_LIBRARY_USE_CONSTEXPR bool operator<=(const LhsType lhs, const static_modint<modulo> rhs) {
  CP_LIBRARY_WARN("static_modint::operator<= : Are you sure you want to do this?");
  return lhs < static_cast<std::int_least32_t>(rhs);
}
template <typename LhsType, std::int_least32_t modulo>
[[nodiscard]] CP_LIBRARY_USE_CONSTEXPR bool operator>(const LhsType lhs, const static_modint<modulo> rhs) {
  CP_LIBRARY_WARN("static_modint::operator> : Are you sure you want to do this?");
  return lhs < static_cast<std::int_least32_t>(rhs);
}
template <typename LhsType, std::int_least32_t modulo>
[[nodiscard]] CP_LIBRARY_USE_CONSTEXPR bool operator>=(const LhsType lhs, const static_modint<modulo> rhs) {
  CP_LIBRARY_WARN("static_modint::operator>= : Are you sure you want to do this?");
  return lhs < static_cast<std::int_least32_t>(rhs);
}

}  // namespace lib

#undef CP_LIBRARY_USE_CONSTEXPR

#ifdef CP_LIBRARY_WARN_NOT_DEFINED
#  undef CP_LIBRARY_WARN
#  undef CP_LIBRARY_WARN_NOT_DEFINED
#  ifdef CP_LIBRARY_WARN
#    undef CP_LIBRARY_WARN
#  endif
#endif

#ifdef CP_LIBRARY_ASSERT_NOT_DEFINED
#  undef CP_LIBRARY_ASSERT
#  undef CP_LIBRARY_ASSERT_NOT_DEFINED
#endif

#endif  // CP_LIBRARY_STATIC_MODINT_HPP
#line 1 "include/data_structure/binary_indexed_tree.hpp"

//! @file binary_indexed_tree.hpp

#ifndef CP_LIBRARY_BINARY_INDEXED_TREE_HPP
#define CP_LIBRARY_BINARY_INDEXED_TREE_HPP

#include <cassert>
#line 9 "include/data_structure/binary_indexed_tree.hpp"
#include <string>
#include <vector>

#ifndef CP_LIBRARY_ASSERT
//! @brief Assert macro
#  define CP_LIBRARY_ASSERT(...) assert(__VA_ARGS__)
#  define CP_LIBRARY_ASSERT_NOT_DEFINED
#endif

namespace lib {

namespace internal::binary_indexed_tree_hpp {
  //! @brief Normal binary indexed tree.
  //! @tparam Elem Element type. Watch out for overflows.
  template <typename Elem>
  class binary_indexed_tree_impl {
  private:
    int length;
    std::vector<Elem> data;

    //! @return Sum of the elements within [0, index) (0-indexed, half-open interval)
    [[nodiscard]] Elem partial_sum(int index) const {
      Elem res = 0;
      for (; index > 0; index -= (index & -index))
        res += data[index];
      return res;
    }

  public:
    //! @brief Construct a vector of n zeroes.
    //! @param n vector size
    explicit binary_indexed_tree_impl(const int n) : length(n), data(n + 1, (Elem) 0) {}

    //! @brief Construct a vector from an existing container.
    //! @tparam Container container type (deduced from parameter).
    //! @param src Source (container)
    template <typename Container>
    explicit binary_indexed_tree_impl(const Container& src)
        : length(static_cast<int>(std::size(src))), data(length + 1, (Elem) 0) {
      for (int i = 0; i < length; ++i)
        add(i, src[i]);
    }

    //! @brief Construct a vector of length n filled with initial_values.
    //! @param n vector size
    //! @param initial_value initial value for all elements
    binary_indexed_tree_impl(const int n, const Elem& initial_value) : length(n), data(n + 1, (Elem) 0) {
      for (int i = 0; i < length; ++i)
        add(i, initial_value);
    }

    //! @return Vector length
    [[nodiscard]] int size() const noexcept {
      return length;
    }

    //! @brief Add value to the index-th element.
    //! @param index index of the element to be added (0-indexed)
    //! @param value value to be added
    //! @note Time complexity: O(log size)
    void add(int index, const Elem& value) {
      CP_LIBRARY_ASSERT(0 <= index && index < length);
      for (++index; index <= length; index += (index & -index))
        data[index] += value;
    }

    //! @brief Calculate interval sum.
    //! @param left lower limit of interval (0-indexed)
    //! @param right upper limit of interval (0-indexed)
    //! @return Sum of the elements within [left, right) (half-open interval)
    //! @note Time complexity: O(log size)
    [[nodiscard]] Elem sum(int left, int right) const {
      CP_LIBRARY_ASSERT(0 <= left && left <= right && right <= length);
      if (left == 0)
        return partial_sum(right);
      else
        return partial_sum(right) - partial_sum(left - 1);
    }

    //! @brief Get the value of the index-th element.
    //! @param index index (0-indexed)
    //! @note Time complexity: O(log size)
    [[nodiscard]] Elem get(int index) const {
      return partial_sum(index + 1) - partial_sum(index);
    }

    //! @brief Set the value of the index-th element to value.
    //! @param index index (0-indexed)
    //! @param value value to be set
    //! @note Time complexity: O(log size)
    void set(const int index, const Elem& value) {
      add(index, value - get(index));
    }
  };
}  // namespace internal::binary_indexed_tree_hpp

//! @brief Binary indexed tree with uniform add function.
//! @tparam Elem Element type. Watch out for overflows.
template <typename Elem>
class binary_indexed_tree {
private:
  internal::binary_indexed_tree_hpp::binary_indexed_tree_impl<Elem> bit_0, bit_1;

  //! @return Sum of the elements within [0, index) (0-indexed, half-open interval)
  [[nodiscard]] Elem partial_sum(int index) const {
    return bit_0.sum(0, index) + bit_1.sum(0, index) * (index - 1);
  }

public:
  //! @brief Construct a vector of n zeroes.
  //! @param n vector size
  explicit binary_indexed_tree(const int n) : bit_0(n), bit_1(n) {}

  //! @brief Construct a vector from an existing container.
  //! @tparam Container container type (deduced from parameter).
  //! @param src Source (container)
  template <typename Container>
  explicit binary_indexed_tree(const Container& src) : bit_0(src), bit_1(static_cast<int>(std::size(src))) {}

  //! @brief Construct a vector of length n filled with initial_values.
  //! @param n vector size
  //! @param initial_value initial value for all elements
  binary_indexed_tree(const int n, const Elem& initial_value) : bit_0(n, initial_value), bit_1(n) {}

  //! @return Vector size (length)
  [[nodiscard]] int size() const noexcept {
    return bit_0.size();
  }

  //! @brief Add value to the index-th element.
  //! @param index index of the element to be added (0-indexed)
  //! @param value value to be added
  //! @note Time complexity: O(log size)
  void add(int index, const Elem& value) {
    bit_0.add(index, value);
  }

  //! @brief Add value to the elements within [left, right) (half-open interval)
  //! @param left lower limit of interval (0-indexed)
  //! @param right upper limit of interval (0-indexed)
  //! @param value value to be added
  //! @note Time complexity: O(log size)
  void uniform_add(int left, int right, const Elem& value) {
    CP_LIBRARY_ASSERT(0 <= left && left <= right && right <= size());
    if (left != size()) {
      bit_0.add(left, value * (-1) * (left - 1));
      bit_1.add(left, value);
    }
    if (right != size()) {
      bit_0.add(right, value * (right - 1));
      bit_1.add(right, value * (-1));
    }
  }

  //! @brief Calculate interval sum.
  //! @param left lower limit of interval (0-indexed)
  //! @param right upper limit of interval (0-indexed)
  //! @return Sum of the elements within [left, right) (half-open interval)
  //! @note Time complexity: O(log size)
  [[nodiscard]] Elem sum(int left, int right) const {
    if (left == 0)
      return partial_sum(right);
    else
      return partial_sum(right) - partial_sum(left - 1);
  }

  //! @brief Get the value of the index-th element.
  //! @param index index (0-indexed)
  //! @note Time complexity: O(log size)
  [[nodiscard]] Elem get(int index) const {
    return partial_sum(index + 1) - partial_sum(index);
  }

  //! @brief Set the value of the index-th element to value.
  //! @param index index (0-indexed)
  //! @param value value to be set
  //! @note Time complexity: O(log size)
  void set(const int index, const Elem& value) {
    bit_0.add(index, value - get(index));
  }

  //! @brief Print debug information.
  //! @param name variable name
  //! @param os output stream
  void debug_print([[maybe_unused]] const std::string& name = "", [[maybe_unused]] std::ostream& os = std::cerr) const {
#if (CP_LIBRARY_DEBUG_LEVEL >= 1)
    if (!name.empty())
      os << name << ": ";

    os << "val [ ";
    for (int i = 0; i < size(); ++i)
      os << get(i) << ' ';
    os << "]\n";

    if (!name.empty())
      os << std::string(std::size(name) + 2, ' ');

    os << "sum [ ";
    for (int i = 0; i <= size(); ++i)
      os << partial_sum(i) << ' ';
    os << "]\n";
#endif
  }
};

}  // namespace lib

#ifdef CP_LIBRARY_ASSERT_NOT_DEFINED
#  undef CP_LIBRARY_ASSERT
#  undef CP_LIBRARY_ASSERT_NOT_DEFINED
#endif

#endif  // CP_LIBRARY_BINARY_INDEXED_TREE_HPP
#line 9 "test/data_structure/binary_indexed_tree/1.test.cpp"

int main() {
  std::ios_base::sync_with_stdio(false);
  std::cin.tie(nullptr);

  int N;
  std::cin >> N;

  std::vector<int> A(N);
  std::copy_n(std::istream_iterator<int>(std::cin), N, std::begin(A));

  std::map<int, int> count;
  std::for_each(std::cbegin(A), std::cend(A), [&](const int a) { ++count[a]; });

  std::vector<std::pair<int, int>> L, R;
  std::for_each(std::cbegin(count), std::cend(count), [&](const auto p) { L.emplace_back(p); R.emplace_back(p); });

  std::sort(std::begin(L), std::end(L));
  std::sort(std::rbegin(R), std::rend(R));

  const int M = static_cast<int>(std::size(L));

  lib::binary_indexed_tree<long long> L_acc(M), R_acc(M);
  lib::binary_indexed_tree<int> L_cnt(M), R_cnt(M);

  for (int i = 0; i < M; i++) {
    L_acc.add(i, L[i].first * L[i].second);
    L_cnt.add(i, L[i].second);
    R_acc.add(i, R[i].first * R[i].second);
    R_cnt.add(i, R[i].second);
  }

  using mint = lib::static_modint<998244353>;

  std::vector<mint> right(N), left(N);
  std::vector<int> rs(N), ls(N);

  for (int i = 0; i < N - 1; i++) {
    const int idx = static_cast<int>(std::distance(std::cbegin(L), std::lower_bound(std::cbegin(L), std::cend(L), std::pair {A[i], 0})));
    L_cnt.add(idx, -1);
    L_acc.add(idx, -A[i]);

    if (i == 0 || idx == 0)
      continue;

    right[i] = mint(L_acc.sum(0, idx));
    rs[i]    = L_cnt.sum(0, idx);
  }

  for (int i = 0; i < N - 1; i++) {
    const int idx = static_cast<int>(std::distance(std::lower_bound(std::crbegin(R), std::crend(R), std::pair {A[N - 1 - i], 0}), std::crend(R)) - 1);
    --R[idx].second;
    R_cnt.add(idx, -1);
    R_acc.add(idx, -A[N - 1 - i]);

    if (i == 0 || idx == 0)
      continue;

    left[i] = mint(R_acc.sum(0, idx));
    ls[i]   = R_cnt.sum(0, idx);
  }

  std::reverse(std::begin(left), std::end(left));
  std::reverse(std::begin(ls), std::end(ls));

  mint res;

  for (int i = 0; i < N - 1; i++) {
    res += mint(right[i]) * ls[i];
    res += mint(left[i]) * rs[i];
    res += mint(A[i]) * rs[i] * ls[i];
  }

  std::cout << res << '\n';
}
Back to top page