Submission #1238755

#	Time	Username	Problem	Language	Result	Execution time	Memory
1238755		CyberCow	Longest Trip (IOI23_longesttrip)	C++20	15 / 100	5 ms	404 KiB

longesttrip

#include "longesttrip.h"
#include <vector>
#include <deque>
#include <algorithm>
using namespace std;

vector<int> operator+(vector<int> x, vector<int> y)
{
	for (int i : y) x.push_back(i);
	return x;
}

vector<int> longest_trip(int N, int D)
{
	vector<int> ans;
	vector<int> a = { 0 }, b = { 1 };
	for (int i = 2; i < N; i++)
	{
		if (are_connected({ a.back() }, { i }))
		{
			a.push_back(i);
		}
		else if (are_connected({ b.back() }, { i }))
		{
			b.push_back(i);
		}
		else
		{
			for (int j = b.size() - 1; j >= 0; j--)
			{
				a.push_back(b[j]);
			}
			b.clear();
			b.push_back(i);
		}
	}
	if (a.size() < b.size())swap(a, b);
	if (are_connected(a, b))
	{
		if (are_connected({ a[0] }, { b[0] }))
		{
			reverse(a.begin(), a.end());
			a = a + b;
			return a;
		}
		if (are_connected({ a[0] }, { b.back()}))
		{
			a = b + a;
			reverse(a.begin(), a.end());
			return a;
		}
		if (are_connected({ a.back()}, {b[0]}))
		{
			a = a + b;
			return a;
		}
		if (are_connected({ a.back() }, { a.back()}))
		{
			reverse(b.begin(), b.end());
			a = a + b;
			return a;
		}
		int l = 0, r = a.size() - 1, ass;
		while (l <= r)
		{
			vector<int> harc;
			int m = (l + r) / 2;
			for (int i = l; i <= m; i++)
			{
				harc.push_back(a[i]);
			}
			if (are_connected(harc, b))
			{
				ass = m;
				r = m - 1;
			}
			else
			{
				l = m + 1;
			}
		}
		l = 0;
		r = b.size() - 1;
		int ass1;
		while (l <= r)
		{
			vector<int> harc;
			int m = (l + r) / 2;
			for (int i = l; i <= m; i++)
			{
				harc.push_back(b[i]);
			}
			if (are_connected(harc, a))
			{
				ass1 = m;
				r = m - 1;
			}
			else
			{
				l = m + 1;
			}
		}
		for (int i = ass + 1; i < a.size(); i++)
		{
			ans.push_back(a[i]);
		}
		for (int i = 0; i <= ass; i++)
		{
			ans.push_back(a[i]);
		}
		for (int i = ass1; i < b.size(); i++)
		{
			ans.push_back(b[i]);
		}
		for (int i = 0; i < ass1; i++)
		{
			ans.push_back(b[i]);
		}
		return ans;
	}
	else
		return a;
	throw;
}

• Subtask 0: 0 / 0
• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 0 / 25
• Subtask 4: 0 / 60