結果
問題 | No.1300 Sum of Inversions |
ユーザー |
![]() |
提出日時 | 2020-12-02 02:57:43 |
言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
結果 |
AC
|
実行時間 | 732 ms / 2,000 ms |
コード長 | 3,106 bytes |
コンパイル時間 | 2,500 ms |
コンパイル使用メモリ | 209,856 KB |
最終ジャッジ日時 | 2025-01-16 12:57:30 |
ジャッジサーバーID (参考情報) |
judge5 / judge1 |
(要ログイン)
ファイルパターン | 結果 |
---|---|
sample | AC * 3 |
other | AC * 34 |
ソースコード
#include <bits/stdc++.h>using namespace std;typedef long long ll;typedef pair<ll, ll> p_ll;template<class T>void debug(T itr1, T itr2) { auto now = itr1; while(now<itr2) { cout << *now << " "; now++; } cout << endl; }#define repr(i,from,to) for (ll i=(ll)from; i<(ll)to; i++)#define all(vec) vec.begin(), vec.end()#define rep(i,N) repr(i,0,N)#define per(i,N) for (int i=(int)N-1; i>=0; i--)const ll MOD = 998244353;const ll LLINF = pow(2,61)-1;const int INF = pow(2,30)-1;vector<ll> fac;void c_fac(int x=pow(10,6)+10) { fac.resize(x,true); rep(i,x) fac[i] = i ? (fac[i-1]*i)%MOD : 1; }ll modpow(ll x, ll p) { ll result = 1, now = 1, pm = x; while (now<=p) { if (p&now) { result = result * pm % MOD; } now*=2; pm = pm*pm % MOD; } returnresult; }ll inv(ll a, ll m=MOD) { ll b = m, x = 1, y = 0; while (b!=0) { int d = a/b; a -= b*d; swap(a,b); x -= y*d; swap(x,y); } return (x+m)%m; }ll nck(ll n, ll k) { return fac[n]*inv(fac[k]*fac[n-k]%MOD)%MOD; }ll gcd(ll a, ll b) { if (a<b) swap(a,b); return b==0 ? a : gcd(b, a%b); }ll lcm(ll a, ll b) { return a/gcd(a,b)*b; }// ----------------------------------------------------------------------// ----------------------------------------------------------------------struct cnt {ll num, sum;cnt operator+ (const cnt &x) const { return (cnt){(num+x.num)%MOD, (sum+x.sum)%MOD }; };cnt operator- (const cnt &x) const { return (cnt){(num-x.num+MOD)%MOD, (sum-x.sum+MOD)%MOD}; };};struct SegTree {ll size;vector<cnt> pos;SegTree(ll N) { size = 1; while(size<N) size<<=1; pos.resize(2*size,{0,0}); }cnt operator[](const ll &x) const { return pos[x+size]; }void set(ll x, const cnt v) { pos[x+size] = v; }void update(ll x, const cnt v) { set(x,v); x+=size; while (x>>=1) operate(x); }cnt query(ll a, ll b) {cnt L = {0,0}, R = {0,0};for (a+=size, b+=size; a<b; a>>=1, b>>=1) {if (a&1) { L = q(L,pos[a]); a++; }if (b&1) { b--; R = q(pos[b],R); }}return q(L,R);}void operate(ll i) { pos[i] = q(pos[i*2], pos[i*2+1]); }cnt q(cnt x, cnt y) { return x + y; }};// ----------------------------------------------------------------------// ----------------------------------------------------------------------int main() {ll N; cin >> N;ll A[N]; rep(i,N) cin >> A[i];map<ll, ll> m; rep(i,N) m[A[i]]++;ll nnum = 0; for (auto &x: m) { x.second = nnum; nnum++; }vector<ll> za(N); rep(i,N) za[i] = m[A[i]];// debug(all(za));SegTree stl(N), str(N);rep(i,N) str.update(za[i],str[za[i]]+(cnt){1,A[i]});ll result = 0;rep(i,N) {cnt l = stl.query(za[i]+1,N), r = str.query(0,za[i]);result = (result+l.sum*r.num%MOD+r.sum*l.num%MOD+A[i]*l.num%MOD*r.num%MOD) % MOD;stl.update(za[i],stl[za[i]]+(cnt){1,A[i]});str.update(za[i],str[za[i]]-(cnt){1,A[i]});// rep(j,N) cout << stl[j].num << "," << stl[j].sum << " "; cout << endl;// rep(j,N) cout << str[j].num << "," << str[j].sum << " "; cout << endl;// cout << result << endl;// cout << "-----------" << endl;}cout << result << endl;return 0;}