結果
問題 | No.2327 Inversion Sum |
ユーザー |
|
提出日時 | 2023-05-28 15:09:21 |
言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
結果 |
AC
|
実行時間 | 145 ms / 2,000 ms |
コード長 | 3,701 bytes |
コンパイル時間 | 4,611 ms |
コンパイル使用メモリ | 267,088 KB |
最終ジャッジ日時 | 2025-02-13 12:36:43 |
ジャッジサーバーID (参考情報) |
judge5 / judge3 |
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ファイルパターン | 結果 |
---|---|
sample | AC * 3 |
other | AC * 30 |
ソースコード
#include <atcoder/all>#include <bits/stdc++.h>using namespace std;#define SZ(x) (int) (x).size()#define REP(i, n) for(int i = 0; i < (n); i++)#define FOR(i, a, b) for(auto i = (a); i < (b); i++)#define For(i, a, b, c) \for(auto i = (a); i != (b); i += (c))#define REPR(i, n) for(auto i = (n) -1; i >= 0; i--)#define ALL(s) (s).begin(), (s).end()#define so(V) sort(ALL(V))#define rev(V) reverse(ALL(V))#define uni(v) v.erase(unique(ALL(v)), (v).end())#define eb emplace_backtypedef unsigned long long ull;typedef long long ll;typedef vector<int> vi;typedef vector<ll> vll;typedef vector<bool> vb;typedef vector<vi> vvi;typedef vector<vll> vvll;typedef pair<int, int> PI;typedef pair<ll, ll> PL;const double EPS = 1e-6;const int MOD = 1e9 + 7;const int INF = (1 << 30);const ll LINF = 1e18;const double math_PI = acos(-1);template<typename T>vector<T> make_v(size_t a) {return vector<T>(a);}template<typename T, typename... Ts>auto make_v(size_t a, Ts... ts) {return vector<decltype(make_v<T>(ts...))>(a, make_v<T>(ts...));}template<typename T, typename V>typename enable_if<is_class<T>::value == 0>::type fill_v(T& t, const V& v) {t = v;}template<typename T, typename V>typename enable_if<is_class<T>::value != 0>::type fill_v(T& t, const V& v) {for(auto& e: t) fill_v(e, v);}template<class T>bool chmax(T& a, const T& b) {if(a < b) {a = b;return true;}return false;}template<class T>bool chmin(T& a, const T& b) {if(a > b) {a = b;return true;}return false;}template<typename S, typename T>istream& operator>>(istream& is, pair<S, T>& p) {cin >> p.first >> p.second;return is;}template<typename T>istream& operator>>(istream& is, vector<T>& vec) {for(T& x: vec) is >> x;return is;}template<typename T>string join(vector<T>& vec, string splitter) {stringstream ss;REP(i, SZ(vec)) {if(i != 0) ss << splitter;ss << vec[i];}return ss.str();}template<typename T>ostream& operator<<(ostream& os, vector<T>& vec) {os << join(vec, " ");return os;}using namespace atcoder;using mint = modint998244353;struct S {mint value;int size;};using F = ll;S op(S a, S b) {return { a.value + b.value, a.size + b.size };}S e() {return { mint(0), 0 };}S mapping(F f, S x) {return { x.value + f * x.size, x.size };}F composition(F f, F g) {return f + g;}F id() {return 0;}int main() {cin.tie(nullptr);ios::sync_with_stdio(false);int N, M;cin >> N >> M;vector<mint> fact(N + 2);fact[0] = mint(1);fact[1] = mint(1);FOR(i, 2, N + 2) {fact[i] = fact[i - 1] * i;}vi A(N, -1);set<int> SE;REP(i, N) SE.insert(i);REP(i, M) {int P, K;cin >> P >> K;P--;K--;A[K] = P;SE.erase(P);}fenwick_tree<ll> fw(N);mint ans = 0;REP(i, N) {if(A[i] != -1) {ans += fw.sum(A[i] + 1, N);fw.add(A[i], 1);}}REP(i, N) {fw.add(i, -fw.sum(i, i + 1));}int rest = N - M;ans *= fact[rest];if(rest >= 2)ans += (mint(rest) * mint(rest - 1) / 2).pow(2)* fact[rest - 2];lazy_segtree<S, op, e, F, mapping, composition, id> seg(vector<S>(rest, { mint(0), 1 }));vi R;for(auto s: SE) {R.push_back(s);}if(rest >= 1) {REP(i, N) {if(A[i] == -1) {ans += seg.all_prod().value* fact[rest - 1];} else {auto it = upper_bound(ALL(R), A[i]);seg.apply(0, it - R.begin(), 1);}}REP(i, rest) {seg.set(i, { mint(0), 1 });}REPR(i, N) {if(A[i] == -1) {ans += seg.all_prod().value* fact[rest - 1];} else {auto it = lower_bound(ALL(R), A[i]);seg.apply(it - R.begin(), rest, 1);}}}cout << ans.val() << endl;return 0;}