結果
問題 | No.2616 中央番目の中央値 |
ユーザー |
|
提出日時 | 2024-01-26 21:35:04 |
言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
結果 |
AC
|
実行時間 | 61 ms / 2,000 ms |
コード長 | 5,583 bytes |
コンパイル時間 | 4,169 ms |
コンパイル使用メモリ | 254,916 KB |
最終ジャッジ日時 | 2025-02-18 23:01:53 |
ジャッジサーバーID (参考情報) |
judge3 / judge5 |
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ファイルパターン | 結果 |
---|---|
other | AC * 37 |
ソースコード
#include<bits/stdc++.h>using namespace std;#define all(a) a.begin(),a.end()#define pb push_back#define sz(a) ((int)a.size())using ll=long long;using u32=unsigned int;using u64=unsigned long long;using i128=__int128;using u128=unsigned __int128;using f128=__float128;using pii=pair<int,int>;using pll=pair<ll,ll>;template<typename T> using vc=vector<T>;template<typename T> using vvc=vc<vc<T>>;template<typename T> using vvvc=vc<vvc<T>>;using vi=vc<int>;using vll=vc<ll>;using vvi=vc<vi>;using vvll=vc<vll>;#define vv(type,name,n,...) \vector<vector<type>> name(n,vector<type>(__VA_ARGS__))#define vvv(type,name,n,m,...) \vector<vector<vector<type>>> name(n,vector<vector<type>>(m,vector<type>(__VA_ARGS__)))template<typename T> using min_heap=priority_queue<T,vector<T>,greater<T>>;template<typename T> using max_heap=priority_queue<T>;// https://trap.jp/post/1224/#define rep1(n) for(ll i=0; i<(ll)(n); ++i)#define rep2(i,n) for(ll i=0; i<(ll)(n); ++i)#define rep3(i,a,b) for(ll i=(ll)(a); i<(ll)(b); ++i)#define rep4(i,a,b,c) for(ll i=(ll)(a); i<(ll)(b); i+=(c))#define cut4(a,b,c,d,e,...) e#define rep(...) cut4(__VA_ARGS__,rep4,rep3,rep2,rep1)(__VA_ARGS__)#define per1(n) for(ll i=((ll)n)-1; i>=0; --i)#define per2(i,n) for(ll i=((ll)n)-1; i>=0; --i)#define per3(i,a,b) for(ll i=((ll)a)-1; i>=(ll)(b); --i)#define per4(i,a,b,c) for(ll i=((ll)a)-1; i>=(ll)(b); i-=(c))#define per(...) cut4(__VA_ARGS__,per4,per3,per2,per1)(__VA_ARGS__)#define rep_subset(i,s) for(ll i=(s); i>=0; i=(i==0?-1:(i-1)&(s)))template<typename T, typename S> constexpr T ifloor(const T a, const S b){return a/b-(a%b&&(a^b)<0);}template<typename T, typename S> constexpr T iceil(const T a, const S b){return ifloor(a+b-1,b);}template<typename T>void sort_unique(vector<T> &vec){sort(vec.begin(),vec.end());vec.resize(unique(vec.begin(),vec.end())-vec.begin());}template<typename T, typename S> constexpr bool chmin(T &a, const S b){if(a>b) return a=b,true; return false;}template<typename T, typename S> constexpr bool chmax(T &a, const S b){if(a<b) return a=b,true; return false;}template<typename T, typename S> istream& operator >> (istream& i, pair<T,S> &p){return i >> p.first >> p.second;}template<typename T, typename S> ostream& operator << (ostream& o, const pair<T,S> &p){return o << p.first << ' ' << p.second;}#ifdef i_am_noob#define bug(...) cerr << "#" << __LINE__ << ' ' << #__VA_ARGS__ << "- ", _do(__VA_ARGS__)template<typename T> void _do(vector<T> x){for(auto i: x) cerr << i << ' ';cerr << "\n";}template<typename T> void _do(set<T> x){for(auto i: x) cerr << i << ' ';cerr << "\n";}template<typename T> void _do(unordered_set<T> x){for(auto i: x) cerr << i << ' ';cerr << "\n";}template<typename T> void _do(T && x) {cerr << x << endl;}template<typename T, typename ...S> void _do(T && x, S&&...y) {cerr << x << ", "; _do(y...);}#else#define bug(...) 777771449#endiftemplate<typename T> void print(vector<T> x){for(auto i: x) cout << i << ' ';cout << "\n";}template<typename T> void print(set<T> x){for(auto i: x) cout << i << ' ';cout << "\n";}template<typename T> void print(unordered_set<T> x){for(auto i: x) cout << i << ' ';cout << "\n";}template<typename T> void print(T && x) {cout << x << "\n";}template<typename T, typename... S> void print(T && x, S&&... y) {cout << x << ' ';print(y...);}template<typename T> istream& operator >> (istream& i, vector<T> &vec){for(auto &x: vec) i >> x; return i;}vvi read_graph(int n, int m, int base=1){vvi adj(n);for(int i=0,u,v; i<m; ++i){cin >> u >> v,u-=base,v-=base;adj[u].pb(v),adj[v].pb(u);}return adj;}vvi read_tree(int n, int base=1){return read_graph(n,n-1,base);}template<typename T, typename S> pair<T,S> operator + (const pair<T,S> &a, const pair<T,S> &b){return {a.first+b.first,a.second+b.second};}template<typename T> constexpr T inf=0;template<> constexpr int inf<int> = 0x3f3f3f3f;template<> constexpr ll inf<ll> = 0x3f3f3f3f3f3f3f3f;template<typename T> vector<T> operator += (vector<T> &a, int val){for(auto &i: a) i+=val; return a;}template<typename T> T isqrt(const T &x){T y=sqrt(x+2); while(y*y>x) y--; return y;}#define ykh mt19937 rng(chrono::steady_clock::now().time_since_epoch().count())#include<atcoder/all>using namespace atcoder;using mint=modint998244353;//using mint=modint1000000007;template<int mod>struct nCr{vector<static_modint<mod>> fac,inv,ifac;void calc(int n){fac.resize(n+1),inv.resize(n+1),ifac.resize(n+1);fac[0]=inv[1]=ifac[0]=1;for(int i=1; i<=n; ++i) fac[i]=fac[i-1]*static_modint<mod>::raw(i);for(int i=2; i<=n; ++i) inv[i]=inv[mod%i]*static_modint<mod>::raw(mod-mod/i);for(int i=1; i<=n; ++i) ifac[i]=ifac[i-1]*inv[i];}static_modint<mod> C(int n, int m){if(m<0||m>n) return 0;return fac[n]*ifac[m]*ifac[n-m];}};nCr<998244353> de;void ahcorz(){int n; cin >> n;de.calc(n+1);vi a(n); cin >> a;rep(n) a[i]--;vi pos(n);rep(n) pos[a[i]]=i;fenwick_tree<int> tree(n);mint res;rep(n){int l1=tree.sum(0,pos[i]);int r1=i-l1;int l2=pos[i]-l1;int r2=(n-1-pos[i])-r1;tree.add(pos[i],1);res+=de.C(r1+l2,r1)*de.C(l1+r2,l1);bug(i,pos[i],l1,r1,l2,r2,res.val());}print(res.val());}signed main(){ios_base::sync_with_stdio(0),cin.tie(0);cout << fixed << setprecision(20);int t=1;//cin >> t;while(t--) ahcorz();}