Submission #791392

#	Time	Username	Problem	Language	Result	Execution time	Memory
791392		tkm_algorithms	Sequence (APIO23_sequence)	C++17	7 / 100	90 ms	34784 KiB

sequence

#include "sequence.h"
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
using namespace std;
template<class T> using Tree = tree<T,null_type,less<T>,rb_tree_tag,tree_order_statistics_node_update>;
#define sz(a) (int)a.size()
#define fi first
#define se second
#define pb push_back
vector<pair<int,int>> v[500000];
Tree<pair<int,int>> S;
map<int,int> tot;
int n;
int sequence(int N, vector<int> a) {
	n = N; int ans = 1;
	for(int i = 0; i < n; i++){
		int j = i;
		while(i<n-1 and a[i]==a[i+1]) i++;
		v[a[i]].pb({j,i-j+1});
		ans = max(ans, i-j+1);
	}
	for(int i = 1; i <= n; i++){
		if(sz(v[i])<2)continue;
		int y = v[i][0].se+v[i][1].se;
		int z = v[i][1].fi-(v[i][0].fi+v[i][0].se);
		int x = v[i][0].fi + n-1-(v[i][1].fi+v[i][1].se-1);
		if(x>=z-y) ans = max(ans, y);
	}
	return ans;
}

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