結果
問題 | No.2327 Inversion Sum |
ユーザー |
👑 ![]() |
提出日時 | 2023-05-28 14:44:31 |
言語 | C++17(gcc12) (gcc 12.3.0 + boost 1.87.0) |
結果 |
AC
|
実行時間 | 62 ms / 2,000 ms |
コード長 | 4,777 bytes |
コンパイル時間 | 20,781 ms |
コンパイル使用メモリ | 270,060 KB |
最終ジャッジ日時 | 2025-02-13 11:58:46 |
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 * 30 |
ソースコード
#pragma GCC target("avx2")#pragma GCC optimize("O3")#pragma GCC optimize("unroll-loops")#include <iostream>#include <iomanip>#include <string>#include <vector>#include <algorithm>#include <functional>#include <stack>#include <queue>#include <map>#include <set>#include <unordered_map>#include <unordered_set>#include <cmath>#include <cassert>#include <ctime>#include <utility>#include <random>#include <tuple>#include <bitset>#include <atcoder/all>using namespace std;using namespace atcoder;typedef long long ll;#define rep(i, n) for (int i = 0; i < (int)(n); i++)#define repr(i, n) for (int i = (int)(n) - 1; i >= 0; i--)#define repk(i, k, n) for (int i = k; i < (int)(n); i++)#define all(v) v.begin(), v.end()#define mod1 1000000007#define mod2 998244353#define mod3 100000007#define vi vector<int>#define vs vector<string>#define vc vector<char>#define vl vector<ll>#define vb vector<bool>#define vvi vector<vector<int>>#define vvc vector<vector<char>>#define vvl vector<vector<ll>>#define vvb vector<vector<bool>>#define vvvi vector<vector<vector<int>>>#define vvvl vector<vector<vector<ll>>>#define pii pair<int,int>#define pil pair<int,ll>#define pli pair<ll, int>#define pll pair<ll, ll>#define vpii vector<pair<int,int>>#define vpll vector<pair<ll,ll>>#define vvpii vector<vector<pair<int,int>>>#define vvpll vector<vector<pair<ll,ll>>>template<typename T> void debug(T e){cerr << e << endl;}template<typename T> void debug(vector<T> &v){rep(i, v.size()){cerr << v[i] << " ";}cerr << endl;}template<typename T> void debug(vector<vector<T>> &v){rep(i, v.size()){rep(j, v[i].size()){cerr << v[i][j] << " ";}cerr << endl;}}template<typename T> void debug(vector<pair<T, T>> &v){rep(i,v.size()){cerr << v[i].first << " " << v[i].second << endl;}}template<typename T> void debug(set<T> &st){for (auto itr = st.begin(); itr != st.end(); itr++){cerr << *itr << " ";}cerr << endl;}template<typename T> void debug(multiset<T> &ms){for (auto itr = ms.begin(); itr != ms.end(); itr++){cerr << *itr << " ";}cerr << endl;}template<typename T> void debug(map<T, T> &mp){for (auto itr = mp.begin(); itr != mp.end(); itr++){cerr << itr->first << " " << itr->second << endl;}}void debug_out(){cerr << endl;}template <typename Head, typename... Tail>void debug_out(Head H, Tail... T){cerr << H << " ";debug_out(T...);}ll my_pow(ll x, ll n, ll mod){// 繰り返し二乗法.x^nをmodで割った余り.ll ret;if (n == 0){ret = 1;}else if (n % 2 == 1){ret = (x * my_pow((x * x) % mod, n / 2, mod)) % mod;}else{ret = my_pow((x * x) % mod, n / 2, mod);}return ret;}ll inv(ll x, ll mod){return my_pow(x, mod - 2, mod);}ll op(ll a, ll b){return a + b;}ll e(){return 0LL;}int main(){ll N, M;cin >> N >> M;vl P(M);vl K(M);rep(i,M){cin >> P[i] >> K[i];P[i]--;K[i]--;}vl fact(N + 3);fact[0] = 1;for (ll i = 0; i < N + 2; i++){fact[i + 1] = (fact[i] * (i + 1)) % mod2;}vpll p(M);rep(i,M){p[i].first = K[i];p[i].second = P[i];}sort(all(p));vl val(N, -1);for (ll i = 0; i < M; i++){val[K[i]] = P[i];}//debug(val);ll ans1 = 0; // 決まっている場所同士segtree<ll, op, e> seg(N);for (ll i = 0; i < N; i++){if (val[i] != -1){ans1 += seg.prod(val[i], N);seg.set(val[i], 1);}}ans1 = ans1 % mod2;ans1 = (ans1 * fact[N - M]) % mod2;ll ans2 = ((N - M) * (N - M - 1) / 2) % mod2; // 決まっていない場所同士ans2 = (ans2 * fact[N - M]) % mod2;ans2 = (ans2 * inv(2LL, mod2)) % mod2;segtree<ll, op, e> seg2(N);ll ans3 = 0; // 決まっている場所と決まっていない場所相互ll cnts = 0;for (ll i = 0; i < M; i++){seg2.set(P[i], 1);}for (ll i = 0; i < N; i++){if (val[i] != -1){ll prd = seg2.prod(val[i] + 1, N);ll num = N - val[i] - 1 - prd;ll prd2 = seg2.prod(0, val[i]);ll num2 = val[i] - prd2;//debug_out(num, cnts);ans3 = (ans3 + (((num * cnts) % mod2) * fact[N - M - 1]) % mod2) % mod2;ans3 = (ans3 + (((num2 * (N - M - cnts)) % mod2) * fact[N - M - 1]) % mod2) % mod2;}else{cnts++;}}//debug_out(ans1, ans2, ans3);cout << (ans1 + ans2 + ans3) % mod2 << endl;}