Tifa's CP Library

:heavy_check_mark: src/test_cpverifier/aizu/alds1_5_d.test.cpp

Depends on

Code

#define PROBLEM "https://onlinejudge.u-aizu.ac.jp/courses/lesson/1/ALDS1/all/ALDS1_5_D"

#include "../../code/io/ios_container.hpp"
#include "../../code/util/inversion.hpp"

int main() {
  std::ios::sync_with_stdio(false);
  std::cin.tie(nullptr);
  u32 n;
  std::cin >> n;
  vecu a(n);
  std::cin >> a;
  std::cout << tifa_libs::inversion(a) << '\n';
  return 0;
}
#line 1 "src/test_cpverifier/aizu/alds1_5_d.test.cpp"
#define PROBLEM "https://onlinejudge.u-aizu.ac.jp/courses/lesson/1/ALDS1/all/ALDS1_5_D"

#line 1 "src/code/io/ios_container.hpp"



#line 1 "src/code/util/traits.hpp"



#line 1 "src/code/util/util.hpp"



#include <bits/stdc++.h>

template <class T>
constexpr T abs(T x) { return x < 0 ? -x : x; }

using i8 = int8_t;
using i16 = int16_t;
using i32 = int32_t;
using i64 = int64_t;
using i128 = __int128_t;
using isz = ptrdiff_t;

using u8 = uint8_t;
using u16 = uint16_t;
using u32 = uint32_t;
using u64 = uint64_t;
using u128 = __uint128_t;
using usz = size_t;

using f32 = float;
using f64 = double;
using f128 = long double;

template <class T>
using ptt = std::pair<T, T>;
template <class T>
using pt3 = std::tuple<T, T, T>;
template <class T>
using pt4 = std::tuple<T, T, T, T>;

template <class T, usz N>
using arr = std::array<T, N>;
template <class T>
using vec = std::vector<T>;
template <class T>
using vvec = vec<vec<T>>;
template <class T>
using v3ec = vec<vvec<T>>;
template <class U, class T>
using vecp = vec<std::pair<U, T>>;
template <class U, class T>
using vvecp = vvec<std::pair<U, T>>;
template <class T>
using vecpt = vec<ptt<T>>;
template <class T>
using vvecpt = vvec<ptt<T>>;

template <class T, class C = std::less<T>>
using pq = std::priority_queue<T, vec<T>, C>;
template <class T>
using pqg = std::priority_queue<T, vec<T>, std::greater<T>>;

using strn = std::string;
using strnv = std::string_view;

using vecu = vec<u32>;
using vvecu = vvec<u32>;
using v3ecu = v3ec<u32>;
using vecu64 = vec<u64>;
using vecb = vec<bool>;
using vvecb = vvec<bool>;

#ifdef ONLINE_JUDGE
#undef assert
#define assert(x) 42
#endif

using namespace std::literals;

constexpr i8 operator""_i8(unsigned long long x) { return (i8)x; }
constexpr i16 operator""_i16(unsigned long long x) { return (i16)x; }
constexpr i32 operator""_i32(unsigned long long x) { return (i32)x; }
constexpr i64 operator""_i64(unsigned long long x) { return (i64)x; }
constexpr isz operator""_iz(unsigned long long x) { return (isz)x; }

constexpr u8 operator""_u8(unsigned long long x) { return (u8)x; }
constexpr u16 operator""_u16(unsigned long long x) { return (u16)x; }
constexpr u32 operator""_u32(unsigned long long x) { return (u32)x; }
constexpr u64 operator""_u64(unsigned long long x) { return (u64)x; }
constexpr usz operator""_uz(unsigned long long x) { return (usz)x; }

inline const auto fn_0 = [](auto&&...) {};
inline const auto fn_is0 = [](auto x) { return x == 0; };


#line 5 "src/code/util/traits.hpp"

namespace tifa_libs {

template <class T>
concept iterable_c = requires(T v) {
  { v.begin() } -> std::same_as<typename T::iterator>;
  { v.end() } -> std::same_as<typename T::iterator>;
};

template <class T>
concept container_c = iterable_c<T> && !std::derived_from<T, std::basic_string<typename T::value_type>>;

template <class T>
constexpr bool is_char_v = std::is_same_v<T, char> || std::is_same_v<T, signed char> || std::is_same_v<T, unsigned char>;
template <class T>
concept char_c = is_char_v<T>;

template <class T>
constexpr bool is_s128_v = std::is_same_v<T, __int128_t> || std::is_same_v<T, __int128>;
template <class T>
concept s128_c = is_s128_v<T>;

template <class T>
constexpr bool is_u128_v = std::is_same_v<T, __uint128_t> || std::is_same_v<T, unsigned __int128>;
template <class T>
concept u128_c = is_u128_v<T>;

template <class T>
constexpr bool is_i128_v = is_s128_v<T> || is_u128_v<T>;
template <class T>
concept i128_c = is_u128_v<T>;

template <class T>
constexpr bool is_int_v = std::is_integral_v<T> || is_i128_v<T>;
template <class T>
concept int_c = is_int_v<T>;

template <class T>
constexpr bool is_sint_v = is_s128_v<T> || (is_int_v<T> && std::is_signed_v<T>);
template <class T>
concept sint_c = is_sint_v<T>;

template <class T>
constexpr bool is_uint_v = is_u128_v<T> || (is_int_v<T> && std::is_unsigned_v<T>);
template <class T>
concept uint_c = is_uint_v<T>;

template <class T>
concept mint_c = requires(T x) {
  { x.mod() } -> uint_c;
  { x.val() } -> uint_c;
};

template <class T>
constexpr bool is_arithm_v = std::is_arithmetic_v<T> || is_int_v<T>;
template <class T>
concept arithm_c = is_arithm_v<T>;

template <class T>
struct to_sint : std::make_signed<T> {};
template <>
struct to_sint<u128> {
  using type = u128;
};
template <>
struct to_sint<i128> {
  using type = u128;
};
template <class T>
using to_sint_t = typename to_sint<T>::type;

template <class T>
struct to_uint : std::make_unsigned<T> {};
template <>
struct to_uint<u128> {
  using type = u128;
};
template <>
struct to_uint<i128> {
  using type = u128;
};
template <class T>
using to_uint_t = typename to_uint<T>::type;

}  // namespace tifa_libs


#line 5 "src/code/io/ios_container.hpp"

template <tifa_libs::container_c T>
std::istream &operator>>(std::istream &is, T &x) {
  for (auto &i : x) is >> i;
  return is;
}
template <tifa_libs::container_c T>
std::ostream &operator<<(std::ostream &os, T const &x) {
  if (x.begin() == x.end()) return os;
  auto it = x.begin();
  os << *it++;
  for (; it != x.end(); ++it) os << ' ' << *it;
  return os;
}


#line 1 "src/code/util/inversion.hpp"



#line 1 "src/code/ds/fenwick.hpp"



#line 1 "src/code/bit/lowbit.hpp"



#line 5 "src/code/bit/lowbit.hpp"

namespace tifa_libs::bit {

template <class T>
constexpr T lowbit(T x) { return T(1) << std::countr_zero(x); }

}  // namespace tifa_libs::bit


#line 5 "src/code/ds/fenwick.hpp"

namespace tifa_libs::ds {

template <class T>
class fenwick {
  vec<T> a;

 public:
  //! [1, sz)
  explicit constexpr fenwick(u32 sz) : a(sz) { assert(sz > 1); }

  //! [pos, sz), pos > 0
  constexpr void add(u32 pos, T const &x) {
    if (!pos) return;
    for (; pos < a.size(); pos += bit::lowbit(pos)) a[pos] += x;
  }
  //! [1, pos)
  constexpr T sum(u32 pos) {
    T ret = 0;
    for (pos = std::min(pos, (u32)a.size() - 1); pos; pos -= bit::lowbit(pos)) ret += a[pos];
    return ret;
  }
  //! for weighted fenwick
  constexpr T kth_max(u32 k) {
    u32 now = 0, n = std::bit_ceil(a.size());
    T s{};
    while (n) {
      u32 to = now | n;
      if (to >= a.size()) continue;
      if (T x = s + a[to]; x < k) {
        now = to;
        s = x;
      }
    }
    return now + 1;
  }
};

}  // namespace tifa_libs::ds


#line 1 "src/code/edh/discretization.hpp"



#line 5 "src/code/edh/discretization.hpp"

namespace tifa_libs {

template <iterable_c T = vec<int>>
constexpr T uniq(T v) {
  std::ranges::sort(v);
  auto [f, l] = std::ranges::unique(v);
  v.erase(f, l);
  return v;
}
template <iterable_c T = vec<int>>
constexpr std::pair<T, vec<u32>> gen_id(T const &v) {
  T _ = uniq(v);
  vec<u32> _1;

  for (u32 i = 0; i < v.size(); ++i) _1.push_back(u32(std::ranges::lower_bound(_, v[i]) - _.begin()));
  return {_, _1};
}

}  // namespace tifa_libs


#line 7 "src/code/util/inversion.hpp"

namespace tifa_libs {

template <class T>
constexpr u64 inversion(vec<T> const& v) {
  u64 ans = 0;
  auto id = gen_id(v).second;
  ds::fenwick<u64> tr(v.size() + 1);
  for (u32 i = 0; i < v.size(); ++i) {
    tr.add(id[i] + 1, 1);
    ans += i + 1 - tr.sum(id[i] + 1);
  }
  return ans;
}

}  // namespace tifa_libs


#line 5 "src/test_cpverifier/aizu/alds1_5_d.test.cpp"

int main() {
  std::ios::sync_with_stdio(false);
  std::cin.tie(nullptr);
  u32 n;
  std::cin >> n;
  vecu a(n);
  std::cin >> a;
  std::cout << tifa_libs::inversion(a) << '\n';
  return 0;
}

Test cases

Env Name Status Elapsed Memory
g++-12 00_sample_00.in :heavy_check_mark: AC 7 ms 4 MB
g++-12 00_sample_01.in :heavy_check_mark: AC 7 ms 4 MB
g++-12 01_small_00.in :heavy_check_mark: AC 7 ms 4 MB
g++-12 01_small_01.in :heavy_check_mark: AC 7 ms 4 MB
g++-12 01_small_02.in :heavy_check_mark: AC 7 ms 4 MB
g++-12 01_small_03.in :heavy_check_mark: AC 7 ms 4 MB
g++-12 02_rand_00.in :heavy_check_mark: AC 7 ms 4 MB
g++-12 02_rand_01.in :heavy_check_mark: AC 7 ms 4 MB
g++-12 02_rand_02.in :heavy_check_mark: AC 7 ms 4 MB
g++-12 02_rand_03.in :heavy_check_mark: AC 7 ms 4 MB
g++-12 02_rand_04.in :heavy_check_mark: AC 7 ms 4 MB
g++-12 02_rand_05.in :heavy_check_mark: AC 7 ms 4 MB
g++-12 02_rand_06.in :heavy_check_mark: AC 7 ms 4 MB
g++-12 02_rand_07.in :heavy_check_mark: AC 7 ms 4 MB
g++-12 03_corner_00.in :heavy_check_mark: AC 7 ms 4 MB
g++-12 03_corner_01.in :heavy_check_mark: AC 7 ms 4 MB
g++-12 03_corner_02.in :heavy_check_mark: AC 7 ms 4 MB
g++-12 04_large_00.in :heavy_check_mark: AC 20 ms 5 MB
g++-12 04_large_01.in :heavy_check_mark: AC 19 ms 5 MB
g++-12 04_large_02.in :heavy_check_mark: AC 20 ms 5 MB
g++-12 04_large_03.in :heavy_check_mark: AC 21 ms 5 MB
g++-12 04_large_04.in :heavy_check_mark: AC 21 ms 5 MB
g++-12 04_large_05.in :heavy_check_mark: AC 24 ms 5 MB
g++-12 04_large_06.in :heavy_check_mark: AC 31 ms 5 MB
g++-12 04_large_07.in :heavy_check_mark: AC 32 ms 5 MB
g++-12 05_maximum_00.in :heavy_check_mark: AC 60 ms 7 MB
g++-12 05_maximum_01.in :heavy_check_mark: AC 34 ms 7 MB
g++-12 05_maximum_02.in :heavy_check_mark: AC 33 ms 7 MB
g++-12 05_maximum_03.in :heavy_check_mark: AC 34 ms 7 MB
g++-12 05_maximum_04.in :heavy_check_mark: AC 53 ms 7 MB
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