結果

問題 No.2327 Inversion Sum
ユーザー jabeejabee
提出日時 2023-06-11 10:40:46
言語 C++17
(gcc 12.3.0 + boost 1.83.0)
結果
AC  
実行時間 57 ms / 2,000 ms
コード長 5,792 bytes
コンパイル時間 4,711 ms
コンパイル使用メモリ 276,624 KB
実行使用メモリ 23,592 KB
最終ジャッジ日時 2024-06-11 00:54:24
合計ジャッジ時間 7,004 ms
ジャッジサーバーID
（参考情報） 		judge4 / judge2
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 36 ms
21,504 KB
testcase_01 AC 55 ms
23,448 KB
testcase_02 AC 48 ms
22,984 KB
testcase_03 AC 34 ms
21,100 KB
testcase_04 AC 57 ms
23,592 KB
testcase_05 AC 35 ms
20,224 KB
testcase_06 AC 50 ms
22,976 KB
testcase_07 AC 41 ms
20,756 KB
testcase_08 AC 31 ms
19,540 KB
testcase_09 AC 55 ms
23,384 KB
testcase_10 AC 34 ms
20,096 KB
testcase_11 AC 31 ms
20,224 KB
testcase_12 AC 31 ms
19,584 KB
testcase_13 AC 30 ms
19,304 KB
testcase_14 AC 46 ms
21,672 KB
testcase_15 AC 56 ms
23,524 KB
testcase_16 AC 42 ms
21,632 KB
testcase_17 AC 34 ms
20,636 KB
testcase_18 AC 35 ms
19,584 KB
testcase_19 AC 40 ms
21,504 KB
testcase_20 AC 32 ms
18,992 KB
testcase_21 AC 30 ms
18,944 KB
testcase_22 AC 30 ms
19,072 KB
testcase_23 AC 28 ms
19,048 KB
testcase_24 AC 31 ms
18,896 KB
testcase_25 AC 31 ms
19,064 KB
testcase_26 AC 32 ms
19,072 KB
testcase_27 AC 30 ms
19,072 KB
testcase_28 AC 30 ms
19,200 KB
testcase_29 AC 29 ms
18,904 KB
testcase_30 AC 29 ms
19,072 KB
testcase_31 AC 29 ms
19,068 KB
testcase_32 AC 28 ms
19,072 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 # 

#include<bits/stdc++.h>
#include <math.h>
#include <algorithm>
#include <iostream>
#include <vector>
#include <atcoder/all>
#include <atcoder/dsu>
#include <atcoder/segtree>
#include <atcoder/lazysegtree>
#include <atcoder/modint>
#include <atcoder/scc>
#include <chrono>
#include <random>
#include <cassert>
#ifndef templete
#define rep(i,a,b) for(int i=a;i<b;i++)
#define rrep(i,a,b) for(int i=a;i>=b;i--)
#define fore(i,a) for(auto &i:a)
#define all(x) (x).begin(),(x).end()

//#include<boost/multiprecision/cpp_int.hpp>
//using namespace boost::multiprecision;
using namespace std;
using namespace atcoder;
//using atmint = modint998244353;
using atmint = modint;
using Graph = vector<vector<int>>;
using P = pair<long long,long long>;
//#pragma GCC optimize ("-O3")
using namespace std; void _main(); int main() { cin.tie(0); ios::sync_with_stdio(false); _main(); }
typedef long long ll; const int inf = INT_MAX / 2; const ll infl = 1LL << 60;
template<class T>bool chmax(T& a, const T& b) { if (a < b) { a = b; return 1; } return 0; }
template<class T>bool chmin(T& a, const T& b) { if (b < a) { a = b; return 1; } return 0; }

//---------------------------------------------------------------------------------------------------

template<int MOD> struct ModInt {
    static const int Mod = MOD; unsigned x; ModInt() : x(0) { }
    ModInt(signed sig) { x = sig < 0 ? sig % MOD + MOD : sig % MOD; }
    ModInt(signed long long sig) { x = sig < 0 ? sig % MOD + MOD : sig % MOD; }
    int get() const { return (int)x; }
    ModInt &operator+=(ModInt that) { if ((x += that.x) >= MOD) x -= MOD; return *this; }
    ModInt &operator-=(ModInt that) { if ((x += MOD - that.x) >= MOD) x -= MOD; return *this; }
    ModInt &operator*=(ModInt that) { x = (unsigned long long)x * that.x % MOD; return *this; }
    ModInt &operator/=(ModInt that) { return *this *= that.inverse(); }
    ModInt operator+(ModInt that) const { return ModInt(*this) += that; }
    ModInt operator-(ModInt that) const { return ModInt(*this) -= that; }
    ModInt operator*(ModInt that) const { return ModInt(*this) *= that; }
    ModInt operator/(ModInt that) const { return ModInt(*this) /= that; }
    ModInt inverse() const { long long a = x, b = MOD, u = 1, v = 0;
        while (b) { long long t = a / b; a -= t * b; std::swap(a, b); u -= t * v; std::swap(u, v); }
        return ModInt(u); }
    bool operator==(ModInt that) const { return x == that.x; }
    bool operator!=(ModInt that) const { return x != that.x; }
    ModInt operator-() const { ModInt t; t.x = x == 0 ? 0 : Mod - x; return t; }
};
template<int MOD> ostream& operator<<(ostream& st, const ModInt<MOD> a) { st << a.get(); return st; };
template<int MOD> ModInt<MOD> operator^(ModInt<MOD> a, unsigned long long k) {
    ModInt<MOD> r = 1; while (k) { if (k & 1) r *= a; a *= a; k >>= 1; } return r; }
template<typename T, int FAC_MAX> struct Comb { vector<T> fac, ifac;
    Comb(){fac.resize(FAC_MAX,1);ifac.resize(FAC_MAX,1);rep(i,1,FAC_MAX)fac[i]=fac[i-1]*i;
        ifac[FAC_MAX-1]=T(1)/fac[FAC_MAX-1];rrep(i,FAC_MAX-2,1)ifac[i]=ifac[i+1]*T(i+1);}
    T aPb(int a, int b) { if (b < 0 || a < b) return T(0); return fac[a] * ifac[a - b]; }
    T aCb(int a, int b) { if (b < 0 || a < b) return T(0); return fac[a] * ifac[a - b] * ifac[b]; }
    T nHk(int n, int k) { if (n == 0 && k == 0) return T(1); if (n <= 0 || k < 0) return 0;
        return aCb(n + k - 1, k); } // nHk = (n+k-1)Ck : n is separator
    T pairCombination(int n) {if(n%2==1)return T(0);return fac[n]*ifac[n/2]/(T(2)^(n/2));}
    // combination of paris for n com.aCb(h+w-2,h-1);
}; 
//typedef ModInt<1000000007> mint;
typedef ModInt<998244353> mint; 
//typedef ModInt<1000000000> mint; 
Comb<mint, 2010101> com;
//vector dp(n+1,vector(n+1,vector<ll>(n+1,0)));
//vector dp(n+1,vector<ll>(n+1,0));
  std::random_device seed_gen;
  std::mt19937 engine(seed_gen());
string ye = "Yes"; string no = "No"; string draw = "Draw";

#endif // templete
//---------------------------------------------------------------------------------------------------
ll calc(vector<ll>l,ll n){
  ll siz = l.size();
  fenwick_tree<ll>fw(n+5);
  ll res = 0;
  rep(i,0,siz){
    res += fw.sum(l[i],n+5);
    fw.add(l[i],1);
  }
  return res;
}
void _main() {
  /*
  rep(i,1,6){
    vector<ll>v;
    rep(j,0,i)v.push_back(j);
    ll res = 0;
    do{
       res += calc(v,i);    
    }while(next_permutation(v.begin(),v.end()));
    cout << res << endl;
  }
  */
  ll n,m;
  cin >> n >> m;
  vector<ll>p(m),k(m);
  vector<ll>c(n,-1);
  vector<ll>l;
  vector<P>lp;
  rep(i,0,m){
    cin >> p[i] >> k[i];
    p[i]--;
    k[i]--;
    c[k[i]] = p[i];
    lp.push_back({k[i],p[i]});
  }
  sort(all(lp));
  rep(i,0,m)l.push_back(lp[i].second);
  ll cnt = 0;
  fenwick_tree<ll>fw(n+5);
  rep(i,0,n){
    fw.add(i,1);
    //if(c[i] != -1){
    //  fw.add(i,-1);
   // }else cnt++;
  }
  rep(i,0,m)fw.add(l[i],-1);
  cnt = n - m;
  mint perm = 1;
  rep(i,1,cnt+1)perm *= i;
  mint ans = 0;
  ll inv = calc(l,n);
 // cout << inv << endl;
 // cout << inv << " " << perm << " " << cnt << endl;
  ans += perm * inv;
  perm = 1;
  rep(i,1,cnt)perm *= i;
  mint add = 1;
  rep(i,1,cnt+1)add *= i;
  add *= cnt;
  add *= cnt-1;
  add /= 4;
  ans += add;
  //cout << ans << endl;
  ll now = 0;
  /*
  rep(i,0,n)cout << fw.sum(i,i+1) << " ";
  cout << endl;
  rep(i,0,n)cout << c[i] << " ";
  cout << endl;
  */
  rep(i,0,n){
    if(c[i] == -1)now++;
    else{
      ll bigger = fw.sum(c[i],n+5);
      mint mbigger = bigger;
   //   cout << mbigger << endl;
      ans += mbigger * now * perm; 
      
      ll smaller = fw.sum(0,c[i]);
      mint msmaller = smaller;
   //   cout << mbigger << endl;
      ans += msmaller * (n - m - now) * perm; 
      
    }
  }
//  cout << ans << endl;
  
  cout << ans << endl;
  
}
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