Submission #936698

#	Time	Username	Problem	Language	Result	Execution time	Memory
936698		JuanJL	Sequence (APIO23_sequence)	C++17	0 / 100	676 ms	100432 KiB

sequence

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp> 

#define fst first 
#define snd second
#define pb push_back
#define forn(i,a,b) for(int i = a; i < b; i++)
#define ALL(x) x.begin(),x.end()
#define SZ(x) (int)x.size()
#define mset(a,v) memset((a),(v),sizeof(a))
#define FIN ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#define dbg(v) cout<<"Line("<<__LINE__<<"): "<<#v<<" = "<<v<<'\n';
#define pi pair<int,int>
#define pll pair<ll,ll>
#define oper(a,b) (a+b)
#define NEUT 0
typedef long long ll;
using namespace std;
using namespace __gnu_pbds;
typedef tree<int,null_type,less<int>,rb_tree_tag,tree_order_statistics_node_update> indexed_set;
typedef tree<int,null_type,less_equal<int>,rb_tree_tag,tree_order_statistics_node_update> indexed_multiset;

ll n; 
vector<ll> a;

struct STree { // segment tree for min over integers
	vector<int> st;int n;
	STree(int n): st(4*n+5,NEUT), n(n) {}
	void upd(int k, int s, int e, int p, int v){
		if(s+1==e){st[k]=v;return;}
		int m=(s+e)/2;
		if(p<m)upd(2*k,s,m,p,v);
		else upd(2*k+1,m,e,p,v);
		st[k]=oper(st[2*k],st[2*k+1]);
	}
	int query(int k, int s, int e, int a, int b){
		if(s>=b||e<=a)return NEUT;
		if(s>=a&&e<=b)return st[k];
		int m=(s+e)/2;
		return oper(query(2*k,s,m,a,b),query(2*k+1,m,e,a,b));
	}
	void upd(int p, int v){upd(1,0,n,p,v);}
	int query(int a, int b){return query(1,0,n,a,b);}
}; 

int sequence(int N, std::vector<int> A) {
	n=N;
	a.clear();
	a.resize(n);
	forn(i,0,n) a[i]=A[i];
	ll res = 0;
	
	STree stree(n);
	
	vector<vector<ll>> p;
	set<ll> vals;
	map<ll,ll> cI;
	
	forn(i,0,n) vals.insert(a[i]);
	
	ll ind = 0;
	for(auto i:vals) cI[i]=ind,ind++;
	
	p.resize(SZ(cI));
	
	forn(i,0,n)	p[cI[a[i]]].pb(i);
	
	ll men = 0;
	ll may = 0;
	ll igu = 0;
	
	ll ini = 0;
	
	forn(i,0,SZ(p)){
		men=0; may = 0; igu = 0;
		ini = 0;
		forn(j,0,SZ(p[i])){
			igu++;
			men=stree.query(p[i][ini],p[i][j]+1);
			may=(((j+1)-ini)-igu)-men;
			while(may>men+igu){
				igu--;
				ini++;
				men=stree.query(p[i][ini],p[i][j]+1);
				may=(((j+1)-ini)-igu)-men;
			}
			res = max(res,igu);
		}
		
		forn(j,0,SZ(p[i])){
			stree.upd(p[i][j],1);
		}
	}
	
	//cout<<res<<'\n';
	
	
	/*
	
	
	
	if(n<=(2*pow(10,3))){
		//Subtasks 1 , 2
		forn(i,0,n){
			indexed_multiset im;
			ll ocurr[n+1];
			mset(ocurr,0);
			forn(j,i,n){
				im.insert(a[j]);
				ocurr[a[j]]++;
				
				res = max(res,ocurr[*im.find_by_order((SZ(im))/2)]);
				if(SZ(im)%2==0) res = max(res,ocurr[*im.find_by_order((SZ(im)/2)-1)]);

			}
		}
	}else{
		vector<vector<ll>> p;
		set<ll> vals;
		map<ll,ll> cI;
		forn(i,0,n) vals.insert(a[i]);
		ll ind = 0;
		for(auto i:vals) cI[i]=ind,ind++;
		p.resize(SZ(cI));
		forn(i,0,n)	p[cI[a[i]]].pb(i);
		
		ll men = 0;
		ll may = 0;
		ll igu = 0;
		forn(i,0,SZ(p)){
			men=0; may = 0; igu = 0;
			forn(j,0,SZ(p[i])){
				if(abs(p[i][j]-p[i][j+1])==1) igu++;
				else break;
			}
			igu++;
			res=max(res,igu);
			res=max(res,SZ(p[i])-(igu));
			if(SZ(p[i])==1) may = 0;
			else may = (p[i][igu]-p[i][igu-1])-1;
			
			men=p[i][0]+((n-1)-p[i][SZ(p[i])-1]);
			//cout<<SZ(p[i])<<" "<<may<<" "<<men<<'\n';
			if(may<=men+SZ(p[i])) res = max(res,(ll)SZ(p[i]));
			
			
			//cout<<res<<" "<<i<<'\n';
		}
	}*/
	return res;
}

• Subtask 1: 0 / 11
• Subtask 2: 0 / 17
• Subtask 3: 0 / 7
• Subtask 4: 0 / 12
• Subtask 5: 0 / 13
• Subtask 6: 0 / 22
• Subtask 7: 0 / 18