Submission #759688

#	Time	Username	Problem	Language	Result	Execution time	Memory
759688		IvanJ	Sequence (APIO23_sequence)	C++17	7 / 100	88 ms	31528 KiB

sequence

#include "sequence.h"
#include<bits/stdc++.h>

#define pb push_back
#define x first
#define y second
#define all(a) (a).begin(), (a).end()

using namespace std;

typedef long long ll;
typedef pair<int, int> ii;

const int maxn = 5e5 + 5;

vector<int> pos[maxn];

int sequence(int N, vector<int> A) {
	for(int i = 0;i < N;i++) pos[A[i]].pb(i);
	
	int X = 0;
	for(int i = 1;i < N;i++) 
		if(A[i] > A[X]) X = i;
	
	int l = 0, ans = 0;
	for(int i = 1;i <= N;i++) {
		if(pos[i].size() == 0) continue;
		int lo = pos[i][0], hi = pos[i].back();
		if(hi < X || lo > X) ans = max(ans, (int)pos[i].size());
		else {
			int e = (int)pos[i].size();
			int g = N - e - l;
			if(l < g - e) {
				int x = 0, y = 0;
				for(int j : pos[i]) 
					if(j < X) x++;
					else y++;
				ans = max(ans, max(x, y));
			} else ans = max(ans, e);
		}
		
		l += (int)pos[i].size();
	}
	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