結果
問題 | No.284 門松と魔法(2) |
ユーザー |
|
提出日時 | 2022-08-31 22:56:47 |
言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
結果 |
TLE
|
実行時間 | - |
コード長 | 4,587 bytes |
コンパイル時間 | 2,984 ms |
コンパイル使用メモリ | 230,440 KB |
最終ジャッジ日時 | 2025-02-07 00:20:37 |
ジャッジサーバーID (参考情報) |
judge1 / judge3 |
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ファイルパターン | 結果 |
---|---|
other | AC * 37 TLE * 3 |
ソースコード
#include<bits/stdc++.h>using namespace std;#pragma GCC optimize("O3")#define rep(i,n) for(ll i=0;i<n;i++)#define repl(i,l,r) for(ll i=(l);i<(r);i++)#define per(i,n) for(ll i=(n)-1;i>=0;i--)#define perl(i,r,l) for(ll i=r-1;i>=l;i--)#define fi first#define se second#define pb push_back#define ins insert#define pqueue(x) priority_queue<x,vector<x>,greater<x>>#define all(x) (x).begin(),(x).end()#define CST(x) cout<<fixed<<setprecision(x)#define vtpl(x,y,z) vector<tuple<x,y,z>>#define rev(x) reverse(x);using ll=long long;using vl=vector<ll>;using vvl=vector<vector<ll>>;using pl=pair<ll,ll>;using vpl=vector<pl>;using vvpl=vector<vpl>;const ll MOD=1000000007;const ll MOD9=998244353;const int inf=1e9+10;const ll INF=4e18;const ll dy[9]={0,1,0,-1,1,1,-1,-1,0};const ll dx[9]={1,0,-1,0,1,-1,1,-1,0};template<class T> inline bool chmin(T& a, T b) {if (a > b) {a = b;return true;}return false;}template<class T> inline bool chmax(T& a, T b) {if (a < b) {a = b;return true;}return false;}//0-indexed,2冪のセグメントツリーtemplate <class T>struct SegTree {private:int n;// 葉の数vector<T> data;// データを格納するvectorT def; // 初期値かつ単位元function<T(T, T)> operation; // 区間クエリで使う処理function<T(T, T)> change;// 点更新で使う処理T find(int a, int b) {T val_left = def, val_right = def;for (a += (n - 1), b += (n - 1); a < b; a >>= 1, b >>= 1){if ((a & 1) == 0){val_left = operation(val_left, data[a]);}if ((b & 1) == 0){val_right = operation(data[--b],val_right);}}return operation(val_left, val_right);}public:// _n:必要サイズ, _def:初期値かつ単位元, _operation:クエリ関数,// _change:更新関数SegTree(size_t _n, T _def, function<T(T, T)> _operation,function<T(T, T)> _change=[](T a,T b){return b;}): def(_def), operation(_operation), change(_change) {n = 1;while (n < _n) {n *= 2;}data = vector<T>(2 * n - 1, def);}void set(int i, T x) { data[i + n - 1] = x; }void build() {for (int k=n-2;k>=0;k--) data[k] = operation(data[2*k+1],data[2*k+2]);}// 場所i(0-indexed)の値をxで更新void update(int i, T x) {i += n - 1;data[i] = change(data[i], x);while (i > 0) {i = (i - 1) / 2;data[i] = operation(data[i * 2 + 1], data[i * 2 + 2]);}}T all_prod(){return data[0];}// [a, b)の区間クエリを実行T query(int a, int b) {//return _query(a, b, 0, 0, n);return find(a,b);}// 添字でアクセスT operator[](int i) {return data[i + n - 1];}};struct node{ll value,i,j;node(ll a,ll b,ll v):value(a),i(b),j(v){}bool operator<(node b){return value>b.value;}};using vn=vector<node>;vn fx(vn a,vn b){for(auto p:b)a.emplace_back(p);sort(all(a));unordered_set<ll> st;unordered_map<ll,ll> degi,degj;vn tmp;for(auto p:a){if(degi[p.i]>=2)continue;if(degj[p.j]>=2)continue;if(st.count(p.i*inf+p.j))continue;degi[p.i]++;degj[p.j]++;st.insert(p.i*inf+p.j);tmp.emplace_back(p);if(tmp.size()==4)break;}return tmp;}vn ex;int main(){ios::sync_with_stdio(false);std::cin.tie(nullptr);ll n;cin >> n;vl v(n);rep(i,n)cin >> v[i];vl pls=v;pls.emplace_back(0);pls.emplace_back(INF);sort(all(pls));pls.erase(unique(all(pls)),pls.end());ll base=pls.size();SegTree<vn> stup(base,ex,fx,fx),stdown=stup;{node p(0,base-1,-INF);vn tmp;tmp.emplace_back(p);stup.update(base-1,tmp);}{node p(0,0,-INF);vn tmp;tmp.emplace_back(p);stdown.update(0,tmp);}rep(i,n){ll a=lower_bound(all(pls),v[i])-pls.begin();{auto f=stup.query(a+1,base);vn ok;for(auto p:f){if(p.j==a)continue;ok.emplace_back(node(p.value+1,a,p.i));}stdown.update(a,ok);}{auto f=stdown.query(0,a);vn ok;for(auto p:f){if(p.j==a)continue;ok.emplace_back(node(p.value+1,a,p.i));}stup.update(a,ok);}}ll ans=0;for(auto p:stup.query(0,base))chmax(ans,p.value);for(auto p:stdown.query(0,base))chmax(ans,p.value);cout << (ans>=3? ans:0) << endl;}