#585101 (C++14) No.1300 Sum of Inversions

提出ソース

結果

問題	No.1300 Sum of Inversions
ユーザー	heno239
提出日時	2020-11-27 21:32:07
言語	C++14 (gcc 12.3.0 + boost 1.83.0)
結果	AC
実行時間	122 ms / 2,000 ms
コード長	4,142 bytes
コンパイル時間	2,392 ms
コンパイル使用メモリ	137,360 KB
実行使用メモリ	12,672 KB
最終ジャッジ日時	2024-07-23 22:15:19
合計ジャッジ時間	6,984 ms
ジャッジサーバーID （参考情報）	judge3 / judge4

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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 6,812 KB
testcase_01	AC	2 ms 6,944 KB
testcase_02	AC	2 ms 6,940 KB
testcase_03	AC	95 ms 10,496 KB
testcase_04	AC	90 ms 10,368 KB
testcase_05	AC	75 ms 8,960 KB
testcase_06	AC	104 ms 11,392 KB
testcase_07	AC	100 ms 11,008 KB
testcase_08	AC	112 ms 11,776 KB
testcase_09	AC	113 ms 11,648 KB
testcase_10	AC	58 ms 7,936 KB
testcase_11	AC	60 ms 8,320 KB
testcase_12	AC	92 ms 10,368 KB
testcase_13	AC	94 ms 10,112 KB
testcase_14	AC	122 ms 12,544 KB
testcase_15	AC	114 ms 11,648 KB
testcase_16	AC	95 ms 10,624 KB
testcase_17	AC	58 ms 7,936 KB
testcase_18	AC	68 ms 8,576 KB
testcase_19	AC	80 ms 9,600 KB
testcase_20	AC	83 ms 9,856 KB
testcase_21	AC	82 ms 9,728 KB
testcase_22	AC	74 ms 9,088 KB
testcase_23	AC	103 ms 11,392 KB
testcase_24	AC	79 ms 9,216 KB
testcase_25	AC	65 ms 8,448 KB
testcase_26	AC	64 ms 8,320 KB
testcase_27	AC	71 ms 8,960 KB
testcase_28	AC	118 ms 12,032 KB
testcase_29	AC	80 ms 9,728 KB
testcase_30	AC	113 ms 11,776 KB
testcase_31	AC	73 ms 9,216 KB
testcase_32	AC	80 ms 9,344 KB
testcase_33	AC	25 ms 6,940 KB
testcase_34	AC	38 ms 6,944 KB
testcase_35	AC	73 ms 12,672 KB
testcase_36	AC	79 ms 12,672 KB

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ソースコード

raw source code

#pragma GCC optimize("Ofast")
#pragma GCC target ("sse4")

#include<iostream>
#include<string>
#include<cstdio>
#include<vector>
#include<cmath>
#include<algorithm>
#include<functional>
#include<iomanip>
#include<queue>
#include<ciso646>
#include<random>
#include<map>
#include<set>
#include<bitset>
#include<stack>
#include<unordered_map>
#include<unordered_set>
#include<utility>
#include<cassert>
#include<complex>
#include<numeric>
#include<array>
using namespace std;

//#define int long long
typedef long long ll;

typedef unsigned long long ul;
typedef unsigned int ui;
constexpr ll mod = 998244353;
const ll INF = mod * mod;
typedef pair<int, int>P;
#define stop char nyaa;cin>>nyaa;
#define rep(i,n) for(int i=0;i<n;i++)
#define per(i,n) for(int i=n-1;i>=0;i--)
#define Rep(i,sta,n) for(int i=sta;i<n;i++)
#define rep1(i,n) for(int i=1;i<=n;i++)
#define per1(i,n) for(int i=n;i>=1;i--)
#define Rep1(i,sta,n) for(int i=sta;i<=n;i++)
#define all(v) (v).begin(),(v).end()
typedef pair<ll, ll> LP;
typedef double ld;
typedef pair<ld, ld> LDP;
const ld eps = 1e-12;
const ld pi = acosl(-1.0);

ll mod_pow(ll x, ll n, ll m = mod) {
	ll res = 1;
	while (n) {
		if (n & 1)res = res * x % m;
		x = x * x % m; n >>= 1;
	}
	return res;
}
struct modint {
	ll n;
	modint() :n(0) { ; }
	modint(ll m) :n(m) {
		if (n >= mod)n %= mod;
		else if (n < 0)n = (n % mod + mod) % mod;
	}
	operator int() { return n; }
};
bool operator==(modint a, modint b) { return a.n == b.n; }
modint operator+=(modint& a, modint b) { a.n += b.n; if (a.n >= mod)a.n -= mod; return a; }
modint operator-=(modint& a, modint b) { a.n -= b.n; if (a.n < 0)a.n += mod; return a; }
modint operator*=(modint& a, modint b) { a.n = ((ll)a.n * b.n) % mod; return a; }
modint operator+(modint a, modint b) { return a += b; }
modint operator-(modint a, modint b) { return a -= b; }
modint operator*(modint a, modint b) { return a *= b; }
modint operator^(modint a, ll n) {
	if (n == 0)return modint(1);
	modint res = (a * a) ^ (n / 2);
	if (n % 2)res = res * a;
	return res;
}

ll inv(ll a, ll p) {
	return (a == 1 ? 1 : (1 - p * inv(p % a, a)) / a + p);
}
modint operator/(modint a, modint b) { return a * modint(inv(b, mod)); }

const int max_n = 1 << 10;
modint fact[max_n], factinv[max_n];
void init_f() {
	fact[0] = modint(1);
	for (int i = 0; i < max_n - 1; i++) {
		fact[i + 1] = fact[i] * modint(i + 1);
	}
	factinv[max_n - 1] = modint(1) / fact[max_n - 1];
	for (int i = max_n - 2; i >= 0; i--) {
		factinv[i] = factinv[i + 1] * modint(i + 1);
	}
}
modint comb(int a, int b) {
	if (a < 0 || b < 0 || a < b)return 0;
	return fact[a] * factinv[b] * factinv[a - b];
}

ll gcd(ll a, ll b) {
	a = abs(a); b = abs(b);
	if (a < b)swap(a, b);
	while (b) {
		ll r = a % b; a = b; b = r;
	}
	return a;
}
struct BIT {
private:
	vector<modint> node; int n;
public:
	BIT(int n_) {
		n = n_; node.resize(n, 0);
	}
	//0-indexed
	void add(int a, modint w) {
		for (int i = a; i < n; i |= i + 1)node[i] += w;
	}
	//[0,a)
	modint sum(int a) {
		modint ret = 0;
		for (int i = a - 1; i >= 0; i = (i & (i + 1)) - 1)ret += node[i];
		return ret;
	}
	//[a,b)
	modint sum(int a, int b) {
		return sum(b) - sum(a);
	}
};



void solve() {
	int n; cin >> n;
	vector<int> a(n);
	rep(i, n)cin >> a[i];
	vector<int> vx = a; sort(all(vx));
	vx.erase(unique(all(vx)), vx.end());
	rep(i, n)a[i] = lower_bound(all(vx), a[i]) - vx.begin();
	vector<int> cl(n), cr(n);
	BIT btl(vx.size());
	rep(i, n) {
		cl[i] = btl.sum(a[i] + 1, vx.size());
		btl.add(a[i], 1);
	}
	BIT btr(vx.size());
	per(i, n) {
		cr[i] = btr.sum(0, a[i]);
		btr.add(a[i], 1);
	}
	modint ans = 0;
	BIT btsl(vx.size());
	rep(i, n) {
		modint s = btsl.sum(a[i] + 1, vx.size());
		ans += s * (modint)cr[i];
		btsl.add(a[i], vx[a[i]]);
	}
	BIT btsr(vx.size());
	per(i, n) {
		modint s = btsr.sum(0, a[i]);
		ans += s * (modint)cl[i];
		btsr.add(a[i], vx[a[i]]);
	}
	rep(i, n)ans += (modint)vx[a[i]] * (modint)cl[i] * (modint)cr[i];
	cout << ans << "\n";
}

signed main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	//cout << fixed << setprecision(15);
	//init_f();
	//init();
	//expr();
	//int t; cin >> t; rep(i, t)
	solve();
	return 0;
}

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結果

テストケース

ソースコード