Submission #1238746

#	Time	Username	Problem	Language	Result	Execution time	Memory
1238746		CyberCow	Longest Trip (IOI23_longesttrip)	C++20	5 / 100	5 ms	404 KiB

longesttrip

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


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] }, { a.back() }))
		{
			if (b.size() == 1)
			{
				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;
					}
				}
				ans.push_back(b[0]);
				for (int i = ass; i < a.size(); i++)
				{
					ans.push_back(a[i]);
				}
				for (int i = 0; i < ass; i++)
				{
					ans.push_back(a[i]);
				}
				return ans;
			}
			if (!are_connected({ b[0] }, { b.back() }))
			{
				if (are_connected({ a.back() }, { b.back() }))
				{
					while (!b.empty())
					{
						a.push_back(b.back());
						b.pop_back();
					}
					return a;
				}
				reverse(b.begin(), b.end());
				while (!b.empty())
				{
					a.push_back(b.back());
					b.pop_back();
				}
				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
		{
			if (are_connected({ a.back() }, { b.back() }))
			{
				while (!b.empty())
				{
					a.push_back(b.back());
					b.pop_back();
				}
				return a;
			}
			reverse(a.begin(), a.end());
			while (!b.empty())
			{
				a.push_back(b.back());
				b.pop_back();
			}
			return a;
		}
	}
	else
		return a;
	throw;
}

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