結果

問題 No.1300 Sum of Inversions
ユーザー KoD
提出日時 2020-11-27 21:33:00
言語 C++17
(gcc 13.3.0 + boost 1.87.0)
結果
AC  
実行時間 206 ms / 2,000 ms
コード長 10,416 bytes
コンパイル時間 1,266 ms
コンパイル使用メモリ 88,872 KB
最終ジャッジ日時 2025-01-16 06:35:53
ジャッジサーバーID
(参考情報)
judge1 / judge4
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ファイルパターン 結果
sample AC * 3
other AC * 34
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ソースコード

diff #
プレゼンテーションモードにする

#line 1 "main.cpp"
/**
* @title Template
*/
#include <iostream>
#include <algorithm>
#include <utility>
#include <numeric>
#include <vector>
#include <array>
#include <cassert>
#line 2 "/Users/kodamankod/Desktop/cpp_programming/Library/other/range.cpp"
#line 4 "/Users/kodamankod/Desktop/cpp_programming/Library/other/range.cpp"
class range {
struct iter {
std::size_t itr;
constexpr iter(std::size_t pos) noexcept: itr(pos) { }
constexpr void operator ++ () noexcept { ++itr; }
constexpr bool operator != (iter other) const noexcept { return itr != other.itr; }
constexpr std::size_t operator * () const noexcept { return itr; }
};
struct reviter {
std::size_t itr;
constexpr reviter(std::size_t pos) noexcept: itr(pos) { }
constexpr void operator ++ () noexcept { --itr; }
constexpr bool operator != (reviter other) const noexcept { return itr != other.itr; }
constexpr std::size_t operator * () const noexcept { return itr; }
};
const iter first, last;
public:
constexpr range(std::size_t first, std::size_t last) noexcept: first(first), last(std::max(first, last)) { }
constexpr iter begin() const noexcept { return first; }
constexpr iter end() const noexcept { return last; }
constexpr reviter rbegin() const noexcept { return reviter(*last - 1); }
constexpr reviter rend() const noexcept { return reviter(*first - 1); }
};
/**
* @title Range
*/
#line 2 "/Users/kodamankod/Desktop/cpp_programming/Library/algebraic/modular.cpp"
#line 2 "/Users/kodamankod/Desktop/cpp_programming/Library/algebraic/mod_inv.cpp"
#line 4 "/Users/kodamankod/Desktop/cpp_programming/Library/algebraic/mod_inv.cpp"
#include <cstdint>
constexpr std::pair<int64_t, int64_t> mod_inv(int64_t a, int64_t b) {
if ((a %= b) == 0) return { b, 0 };
int64_t s = b, t = (a < 0 ? a + b : a);
int64_t m0 = 0, m1 = 1, tmp = 0;
while (t > 0) {
const auto u = s / t;
s -= t * u; m0 -= m1 * u;
tmp = s; s = t; t = tmp; tmp = m0; m0 = m1; m1 = tmp;
}
return { s, (m0 < 0 ? m0 + b / s : m0) };
}
/**
* @title Extended GCD
*/
#line 4 "/Users/kodamankod/Desktop/cpp_programming/Library/algebraic/modular.cpp"
#line 8 "/Users/kodamankod/Desktop/cpp_programming/Library/algebraic/modular.cpp"
#include <type_traits>
template <class Modulus>
class modular {
public:
using value_type = uint32_t;
using cover_type = uint64_t;
static constexpr uint32_t mod() { return Modulus::mod(); }
template <class T>
static constexpr value_type normalize(T value_) noexcept {
if (value_ < 0) {
value_ = -value_;
value_ %= mod();
if (value_ == 0) return 0;
return mod() - value_;
}
return value_ % mod();
}
private:
value_type value;
template <bool IsPrime, std::enable_if_t<IsPrime>* = nullptr>
constexpr modular inverse_helper() const noexcept { return power(*this, mod() - 2); }
template <bool IsPrime, std::enable_if_t<!IsPrime>* = nullptr>
constexpr modular inverse_helper() const noexcept {
const auto tmp = mod_inv(value, mod());
assert(tmp.first == 1);
return modular(tmp.second);
}
public:
constexpr modular() noexcept : value(0) { }
template <class T>
explicit constexpr modular(T value_) noexcept : value(normalize(value_)) { }
template <class T>
explicit constexpr operator T() const noexcept { return static_cast<T>(value); }
constexpr value_type get() const noexcept { return value; }
constexpr value_type &extract() noexcept { return value; }
constexpr modular operator - () const noexcept { return modular(mod() - value); }
constexpr modular operator ~ () const noexcept { return inverse(*this); }
constexpr modular operator + (const modular &rhs) const noexcept { return modular(*this) += rhs; }
constexpr modular& operator += (const modular &rhs) noexcept {
if ((value += rhs.value) >= mod()) value -= mod();
return *this;
}
constexpr modular operator - (const modular &rhs) const noexcept { return modular(*this) -= rhs; }
constexpr modular& operator -= (const modular &rhs) noexcept {
if ((value += mod() - rhs.value) >= mod()) value -= mod();
return *this;
}
constexpr modular operator * (const modular &rhs) const noexcept { return modular(*this) *= rhs; }
constexpr modular& operator *= (const modular &rhs) noexcept {
value = (cover_type) value * rhs.value % mod();
return *this;
}
constexpr modular operator / (const modular &rhs) const noexcept { return modular(*this) /= rhs; }
constexpr modular& operator /= (const modular &rhs) noexcept { return (*this) *= inverse(rhs); }
constexpr bool zero() const noexcept { return value == 0; }
constexpr bool operator == (const modular &rhs) const noexcept { return value == rhs.value; }
constexpr bool operator != (const modular &rhs) const noexcept { return value != rhs.value; }
friend std::ostream& operator << (std::ostream &stream, const modular &rhs) { return stream << rhs.value; }
friend constexpr modular inverse(const modular &val) noexcept { return val.inverse_helper<Modulus::is_prime>(); }
friend constexpr modular power(modular val, cover_type exp) noexcept {
modular res(1);
for (; exp > 0; exp >>= 1, val *= val) if (exp & 1) res *= val;
return res;
}
};
template <uint32_t Mod, bool IsPrime = true>
struct static_modulus {
static constexpr uint32_t mod() noexcept { return Mod; }
static constexpr bool is_prime = IsPrime;
};
template <uint32_t Id = 0, bool IsPrime = false>
struct dynamic_modulus {
static uint32_t &mod() noexcept { static uint32_t val = 0; return val; }
static constexpr bool is_prime = IsPrime;
};
template <uint32_t Mod, bool IsPrime = true>
using mint32_t = modular<static_modulus<Mod, IsPrime>>;
using rmint32_t = modular<dynamic_modulus<>>;
/*
* @title Modint
*/
#line 2 "/Users/kodamankod/Desktop/cpp_programming/Library/container/fenwick_tree.cpp"
#line 2 "/Users/kodamankod/Desktop/cpp_programming/Library/other/bit_operation.cpp"
#include <cstddef>
#line 5 "/Users/kodamankod/Desktop/cpp_programming/Library/other/bit_operation.cpp"
constexpr size_t bit_ppc(const uint64_t x) { return __builtin_popcountll(x); }
constexpr size_t bit_ctzr(const uint64_t x) { return x == 0 ? 64 : __builtin_ctzll(x); }
constexpr size_t bit_ctzl(const uint64_t x) { return x == 0 ? 64 : __builtin_clzll(x); }
constexpr size_t bit_width(const uint64_t x) { return 64 - bit_ctzl(x); }
constexpr uint64_t bit_msb(const uint64_t x) { return x == 0 ? 0 : uint64_t(1) << (bit_width(x) - 1); }
constexpr uint64_t bit_lsb(const uint64_t x) { return x & (-x); }
constexpr uint64_t bit_cover(const uint64_t x) { return x == 0 ? 0 : bit_msb(2 * x - 1); }
constexpr uint64_t bit_rev(uint64_t x) {
x = ((x >> 1) & 0x5555555555555555) | ((x & 0x5555555555555555) << 1);
x = ((x >> 2) & 0x3333333333333333) | ((x & 0x3333333333333333) << 2);
x = ((x >> 4) & 0x0F0F0F0F0F0F0F0F) | ((x & 0x0F0F0F0F0F0F0F0F) << 4);
x = ((x >> 8) & 0x00FF00FF00FF00FF) | ((x & 0x00FF00FF00FF00FF) << 8);
x = ((x >> 16) & 0x0000FFFF0000FFFF) | ((x & 0x0000FFFF0000FFFF) << 16);
x = (x >> 32) | (x << 32);
return x;
}
/**
* @title Bit Operations
*/
#line 4 "/Users/kodamankod/Desktop/cpp_programming/Library/container/fenwick_tree.cpp"
#line 8 "/Users/kodamankod/Desktop/cpp_programming/Library/container/fenwick_tree.cpp"
#include <type_traits>
template <class T>
class fenwick_tree {
public:
using value_type = T;
using size_type = size_t;
private:
std::vector<value_type> M_tree;
public:
fenwick_tree() = default;
explicit fenwick_tree(size_type size) { initialize(size); }
void initialize(size_type size) {
M_tree.assign(size + 1, value_type { });
}
void add(size_type index, const value_type& x) {
assert(index < size());
++index;
while (index <= size()) {
M_tree[index] += x;
index += bit_lsb(index);
}
}
template <size_type Indexed = 1>
value_type get(size_type index) const {
assert(index < size());
index += Indexed;
value_type res{ };
while (index > 0) {
res += M_tree[index];
index -= bit_lsb(index);
}
return res;
}
value_type fold(size_type first, size_type last) const {
assert(first <= last);
assert(last <= size());
value_type res{};
while (first < last) {
res += M_tree[last];
last -= bit_lsb(last);
}
while (last < first) {
res -= M_tree[first];
first -= bit_lsb(first);
}
return res;
}
template <class Func>
size_type satisfies(const size_type left, Func &&func) const {
assert(left <= size());
if (func(value_type { })) return left;
value_type val = -get<0>(left);
size_type res = 0;
for (size_type cur = bit_cover(size() + 1) >> 1; cur > 0; cur >>= 1) {
if ((res + cur <= left) || (res + cur <= size() && !func(val + M_tree[res + cur]))) {
val += M_tree[res + cur];
res += cur;
}
}
return res + 1;
}
void clear() {
M_tree.clear();
M_tree.shrink_to_fit();
}
size_type size() const {
return M_tree.size() - 1;
}
};
/**
* @title Fenwick Tree
*/
#line 17 "main.cpp"
using i32 = std::int32_t;
using i64 = std::int64_t;
using u32 = std::uint32_t;
using u64 = std::uint64_t;
using isize = std::ptrdiff_t;
using usize = std::size_t;
constexpr i32 inf32 = (i32(1) << 30) - 1;
constexpr i64 inf64 = (i64(1) << 62) - 1;
using Fp = mint32_t<998244353>;
int main() {
usize N;
std::cin >> N;
std::vector<u32> A(N);
for (auto &x: A) {
std::cin >> x;
}
auto cmp = A;
std::sort(cmp.begin(), cmp.end());
cmp.erase(std::unique(cmp.begin(), cmp.end()), cmp.end());
std::vector<usize> idx(N);
for (auto i: range(0, N)) {
idx[i] = std::lower_bound(cmp.begin(), cmp.end(), A[i]) - cmp.begin();
}
fenwick_tree<Fp> lcnt(cmp.size()), rcnt(cmp.size());
fenwick_tree<Fp> lsum(cmp.size()), rsum(cmp.size());
for (auto i: range(0, N)) {
rcnt.add(idx[i], Fp(1));
rsum.add(idx[i], Fp(A[i]));
}
Fp ans;
for (auto i: range(0, N)) {
rcnt.add(idx[i], -Fp(1));
rsum.add(idx[i], -Fp(A[i]));
const auto L = lcnt.fold(idx[i] + 1, cmp.size());
const auto R = rcnt.fold(0, idx[i]);
ans += L * rsum.fold(0, idx[i]) + R * lsum.fold(idx[i] + 1, cmp.size()) + L * R * Fp(A[i]);
lcnt.add(idx[i], Fp(1));
lsum.add(idx[i], Fp(A[i]));
}
std::cout << ans << '\n';
return 0;
}
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