結果

問題 No.1300 Sum of Inversions
ユーザー nok0nok0
提出日時 2020-11-03 00:18:21
言語 C++17
(gcc 12.3.0 + boost 1.83.0)
結果
AC  
実行時間 109 ms / 2,000 ms
コード長 9,280 bytes
コンパイル時間 2,513 ms
コンパイル使用メモリ 212,636 KB
実行使用メモリ 9,472 KB
最終ジャッジ日時 2024-07-22 08:32:37
合計ジャッジ時間 6,269 ms
ジャッジサーバーID
（参考情報） 		judge1 / judge4
このコードへのチャレンジ
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テストケース

テストケース表示
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 1 ms
5,376 KB
testcase_03 AC 85 ms
7,940 KB
testcase_04 AC 81 ms
7,716 KB
testcase_05 AC 67 ms
7,040 KB
testcase_06 AC 95 ms
8,576 KB
testcase_07 AC 91 ms
8,332 KB
testcase_08 AC 102 ms
8,720 KB
testcase_09 AC 103 ms
8,832 KB
testcase_10 AC 56 ms
6,944 KB
testcase_11 AC 56 ms
6,940 KB
testcase_12 AC 82 ms
7,748 KB
testcase_13 AC 82 ms
7,904 KB
testcase_14 AC 109 ms
9,472 KB
testcase_15 AC 101 ms
8,804 KB
testcase_16 AC 83 ms
8,192 KB
testcase_17 AC 51 ms
6,940 KB
testcase_18 AC 59 ms
6,940 KB
testcase_19 AC 72 ms
7,208 KB
testcase_20 AC 74 ms
7,424 KB
testcase_21 AC 74 ms
7,424 KB
testcase_22 AC 67 ms
7,040 KB
testcase_23 AC 95 ms
8,584 KB
testcase_24 AC 69 ms
7,296 KB
testcase_25 AC 59 ms
6,940 KB
testcase_26 AC 58 ms
6,940 KB
testcase_27 AC 64 ms
7,048 KB
testcase_28 AC 104 ms
8,960 KB
testcase_29 AC 73 ms
7,552 KB
testcase_30 AC 101 ms
8,832 KB
testcase_31 AC 65 ms
7,040 KB
testcase_32 AC 70 ms
7,296 KB
testcase_33 AC 22 ms
7,936 KB
testcase_34 AC 36 ms
7,936 KB
testcase_35 AC 65 ms
9,408 KB
testcase_36 AC 71 ms
9,408 KB
権限があれば一括ダウンロードができます

ソースコード

diff # 

/**
 *	author: nok0
 *	created: 2020.11.02 18:14:48
**/
#ifdef LOCAL
#define _GLIBCXX_DEBUG
#endif
#include <bits/stdc++.h>
using namespace std;
#pragma region Macros
#define FOR(i, l, r) for(int i = (l); i < (r); ++i)
#define REP(i, n) FOR(i, 0, n)
#define REPS(i, n) FOR(i, 1, n + 1)
#define RFOR(i, l, r) for(int i = (l); i >= (r); --i)
#define RREP(i, n) RFOR(i, n - 1, 0)
#define RREPS(i, n) RFOR(i, n, 1)
#define pb push_back
#define eb emplace_back
#define SZ(x) ((int)(x).size())
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
template <class T = int>
using V = vector<T>;
template <class T = int>
using VV = V<V<T>>;
using ll = long long;
using ld = long double;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
#define VEC(type, name, size) \
	V<type> name(size);       \
	INPUT(name)
#define VVEC(type, name, h, w)    \
	VV<type> name(h, V<type>(w)); \
	INPUT(name)
#define INT(...)     \
	int __VA_ARGS__; \
	INPUT(__VA_ARGS__)
#define LL(...)     \
	ll __VA_ARGS__; \
	INPUT(__VA_ARGS__)
#define STR(...)        \
	string __VA_ARGS__; \
	INPUT(__VA_ARGS__)
#define CHAR(...)     \
	char __VA_ARGS__; \
	INPUT(__VA_ARGS__)
#define DOUBLE(...)     \
	DOUBLE __VA_ARGS__; \
	INPUT(__VA_ARGS__)
#define LD(...)     \
	LD __VA_ARGS__; \
	INPUT(__VA_ARGS__)
void scan(int &a) { cin >> a; }
void scan(long long &a) { cin >> a; }
void scan(char &a) { cin >> a; }
void scan(double &a) { cin >> a; }
void scan(long double &a) { cin >> a; }
void scan(char a[]) { scanf("%s", a); }
void scan(string &a) { cin >> a; }
template <class T>
void scan(V<T> &);
template <class T, class L>
void scan(pair<T, L> &);
template <class T>
void scan(V<T> &a) {
	for(auto &i : a) scan(i);
}
template <class T, class L>
void scan(pair<T, L> &p) {
	scan(p.first);
	scan(p.second);
}
template <class T>
void scan(T &a) { cin >> a; }
void INPUT() {}
template <class Head, class... Tail>
void INPUT(Head &head, Tail &... tail) {
	scan(head);
	INPUT(tail...);
}
template <class T>
inline void print(T x) { cout << x << '\n'; }
template <typename T1, typename T2>
istream &operator>>(istream &is, pair<T1, T2> &p) {
	is >> p.first >> p.second;
	return is;
}
template <typename T1, typename T2>
ostream &operator<<(ostream &os, const pair<T1, T2> &p) {
	os << p.first << " " << p.second;
	return os;
}
template <typename T>
istream &operator>>(istream &is, vector<T> &v) {
	for(T &in : v) is >> in;
	return is;
}
template <class T>
ostream &operator<<(ostream &os, const V<T> &v) {
	REP(i, SZ(v)) {
		if(i) os << " ";
		os << v[i];
	}
	return os;
}
//debug
template <typename T>
void view(const V<T> &v) {
	cerr << "{ ";
	for(const auto &e : v) {
		cerr << e << ", ";
	}
	cerr << "\b\b }";
}
template <typename T>
void view(const VV<T> &vv) {
	cerr << "{\n";
	for(const auto &v : vv) {
		cerr << "\t";
		view(v);
		cerr << "\n";
	}
	cerr << "}";
}
template <typename T, typename U>
void view(const V<pair<T, U>> &v) {
	cerr << "{\n";
	for(const auto &c : v) cerr << "\t(" << c.first << ", " << c.second << ")\n";
	cerr << "}";
}
template <typename T, typename U>
void view(const map<T, U> &m) {
	cerr << "{\n";
	for(auto &t : m) cerr << "\t[" << t.first << "] : " << t.second << "\n";
	cerr << "}";
}
template <typename T, typename U>
void view(const pair<T, U> &p) { cerr << "(" << p.first << ", " << p.second << ")"; }
template <typename T>
void view(const set<T> &s) {
	cerr << "{ ";
	for(auto &t : s) {
		view(t);
		cerr << ", ";
	}
	cerr << "\b\b }";
}
template <typename T>
void view(T e) { cerr << e; }
#ifdef LOCAL
void debug_out() {}
template <typename Head, typename... Tail>
void debug_out(Head H, Tail... T) {
	view(H);
	cerr << ", ";
	debug_out(T...);
}
#define debug(...)                                           \
	do {                                                     \
		cerr << __LINE__ << " [" << #__VA_ARGS__ << "] : ["; \
		debug_out(__VA_ARGS__);                              \
		cerr << "\b\b]\n";                                   \
	} while(0)
#else
#define debug(...) (void(0))
#endif
template <class T>
V<T> press(V<T> &x) {
	V<T> res = x;
	sort(all(res));
	res.erase(unique(all(res)), res.end());
	REP(i, SZ(x)) {
		x[i] = lower_bound(all(res), x[i]) - res.begin();
	}
	return res;
}
template <class T>
inline bool chmin(T &a, T b) {
	if(a > b) {
		a = b;
		return true;
	}
	return false;
}
template <class T>
inline bool chmax(T &a, T b) {
	if(a < b) {
		a = b;
		return true;
	}
	return false;
}
inline void Yes(bool b = true) { cout << (b ? "Yes" : "No") << '\n'; }
inline void YES(bool b = true) { cout << (b ? "YES" : "NO") << '\n'; }
inline void err(bool b = true) {
	if(b) {
		cout << -1 << '\n';
		exit(0);
	}
}
template <class T>
inline void fin(bool b = true, T e = 0) {
	if(b) {
		cout << e << '\n';
		exit(0);
	}
}
template <class T>
T divup(T x, T y) { return (x + (y - 1)) / y; }
template <typename T>
T pow(T a, long long n, T e = 1) {
	T ret = e;
	while(n) {
		if(n & 1) ret *= a;
		a *= a;
		n >>= 1;
	}
	return ret;
}
struct iofast {
	iofast() {
		ios::sync_with_stdio(false);
		cin.tie(nullptr);
		cout << fixed << setprecision(15);
	}
} iofast_;
const int inf = 1e9;
const ll INF = 1e18;
#pragma endregion

// Binary Indexed Tree (Fenwick Tree)
template <typename T>
struct BIT {
	int n, p;
	vector<T> d;
	BIT(int n = 0) : n(n), d(n + 1) {
		p = 1;
		while(p < n) p *= 2;
	}
	//更新
	void add(int i, T x = 1) {
		for(i++; i <= n; i += i & -i) d[i] += x;
	}
	//[0,i)の和
	T sum(int i) {
		T res = 0;
		for(; i; i -= i & -i) res += d[i];
		return res;
	}
	//[l,r)の和
	T sum(int l, int r) { return sum(r) - sum(l); }
	//v0+v1+…vx>=mを満たすmin(x)を返す
	int lower_bound(T w) {
		if(w <= 0) return 0;
		T x = 0;
		for(int i = p; i; i /= 2) {
			if(i + x <= n && d[i + x] < w) {
				w -= d[i + x];
				x += i;
			}
		}
		return x;
	}
};

//ModInt
template <const int &mod>
struct ModInt {
private:
	int x;

public:
	ModInt() : x(0) {}

	ModInt(long long x_) {
		if((x = x_ % mod + mod) >= mod) x -= mod;
	}

	int val() const { return x; }

	static int get_mod() { return mod; }

	constexpr ModInt &operator+=(ModInt rhs) {
		if((x += rhs.x) >= mod) x -= mod;
		return *this;
	}

	constexpr ModInt &operator-=(ModInt rhs) {
		if((x -= rhs.x) < 0) x += mod;
		return *this;
	}

	constexpr ModInt &operator*=(ModInt rhs) {
		x = (unsigned long long)x * rhs.x % mod;
		return *this;
	}

	constexpr ModInt &operator/=(ModInt rhs) {
		x = (unsigned long long)x * rhs.inv().x % mod;
		return *this;
	}

	constexpr ModInt operator-() const noexcept { return -x < 0 ? mod - x : -x; }

	constexpr ModInt operator+(ModInt rhs) const noexcept { return ModInt(*this) += rhs; }

	constexpr ModInt operator-(ModInt rhs) const noexcept { return ModInt(*this) -= rhs; }

	constexpr ModInt operator*(ModInt rhs) const noexcept { return ModInt(*this) *= rhs; }

	constexpr ModInt operator/(ModInt rhs) const noexcept { return ModInt(*this) /= rhs; }

	constexpr ModInt &operator++() {
		*this += 1;
		return *this;
	}

	constexpr ModInt operator++(int) {
		*this += 1;
		return *this - 1;
	}

	constexpr ModInt &operator--() {
		*this -= 1;
		return *this;
	}

	constexpr ModInt operator--(int) {
		*this -= 1;
		return *this + 1;
	}

	bool operator==(ModInt rhs) const { return x == rhs.x; }

	bool operator!=(ModInt rhs) const { return x != rhs.x; }

	bool operator<=(ModInt rhs) const { return x <= rhs.x; }

	bool operator>=(ModInt rhs) const { return x >= rhs.x; }

	bool operator<(ModInt rhs) const { return x < rhs.x; }

	bool operator>(ModInt rhs) const { return x > rhs.x; }

	ModInt inv() {
		int a = x, b = mod, u = 1, v = 0, t;
		while(b > 0) {
			t = a / b;
			std::swap(a -= t * b, b);
			std::swap(u -= t * v, v);
		}
		return ModInt(u);
	}

	ModInt pow(long long n) const {
		ModInt ret(1), mul(x);
		while(n > 0) {
			if(n & 1) ret *= mul;
			mul *= mul;
			n >>= 1;
		}
		return ret;
	}

	ModInt sqrt() const {
		if(x <= 1) return x;
		int v = (mod - 1) / 2;
		if(pow(v) != 1) return -1;
		int q = mod - 1, m = 0;
		while(~q & 1) q >>= 1, m++;
		std::mt19937 mt;
		ModInt z = mt();
		while(z.pow(v) != mod - 1) z = mt();
		ModInt c = z.pow(q), t = pow(q), r = pow((q + 1) / 2);
		for(; m > 1; m--) {
			ModInt tmp = t.pow(1 << (m - 2));
			if(tmp != 1) r = r * c, t = t * c * c;
			c = c * c;
		}
		return std::min(r.x, mod - r.x);
	}

	friend std::ostream &operator<<(std::ostream &s, ModInt<mod> a) {
		s << a.x;
		return s;
	}

	friend std::istream &operator>>(std::istream &s, ModInt<mod> &a) {
		s >> a.x;
		return s;
	}
};
static int MOD = 998244353;
using mint = ModInt<MOD>;

mint res;
int main() {
	INT(n);
	VEC(int, a, n);
	assert(n >= 3);

	auto rec = press(a);
	int m = SZ(rec);

	V<mint> left(n), right(n);
	V<int> lk(n), rk(n);
	{
		BIT<mint> BT(m);
		BIT<int> kosuu(m);
		REP(i, n) {
			BT.add(a[i], rec[a[i]]);
			kosuu.add(a[i], 1);
			left[i] = BT.sum(0, m) - BT.sum(0, a[i] + 1);
			lk[i] = kosuu.sum(0, m) - kosuu.sum(0, a[i] + 1);
		}
	}

	{
		BIT<mint> BT(m);
		BIT<int> kosuu(m);
		RREP(i, n) {
			BT.add(a[i], rec[a[i]]);
			kosuu.add(a[i], 1);
			right[i] = BT.sum(0, a[i]);
			rk[i] = kosuu.sum(0, a[i]);
		}
	}

	REP(i, n) {
		if(lk[i] == 0 or rk[i] == 0) continue;
		mint tmp = rec[a[i]];
		res += left[i] * rk[i] + right[i] * lk[i] + tmp * lk[i] * rk[i];
	}

	print(res);
}
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