Trio

DustinTrio.cpp

#include "pch.h"
#include <iostream>
#include <vector>

int dustinBestTrio(int friend_nodes, int friends_from[], int friends_to[])
{
	std::vector<std::vector<int>> allfriends(friend_nodes);

	int i = 0;
	int f = friends_from[i];
	int t = friends_to[i];
	while (f >= 0)
	{
		if (f == t)
		{
			std::cout << "from should not equal to to" << std::endl;
			break;
		}

		allfriends[f].push_back(t);
		allfriends[t].push_back(f);

		i++;
		f = friends_from[i];
		t = friends_to[i];
	}

	int highscore = -1;
	for(int self = 0; self < allfriends.size(); self++)
	{
		for(int n = 0; n < allfriends[self].size(); n++)
		{
			int nextfriend = allfriends[self][n];
			for(int sn = 0; sn < allfriends[nextfriend].size(); sn++)
			{
				int friendsinnextfriend = allfriends[nextfriend][sn];
				if (friendsinnextfriend == self)
				{
					// Duo
					continue;
				}

				for(int tn = 0; tn < allfriends[friendsinnextfriend].size(); tn++)
				{
					int friendsinnextnextfriend = allfriends[friendsinnextfriend][tn];
					if (friendsinnextnextfriend == self)
					{
						// Trio!
						int score = (allfriends[self].size() - 2) + (allfriends[nextfriend].size() - 2) + (allfriends[friendsinnextfriend].size() - 2);
						if (score > highscore)
						{
							highscore = score;
						}
						continue;
					}
				}

			}
		}
	}

	return highscore;
}

int main()
{
	int from[] = { 0, 1, 3, 1, 2, 5, -1 };
	int to[] = { 1, 3, 4, 4, 4, 4, -1 };
	std::cout << dustinBestTrio(6, from, to) << std::endl;
}

DustinTrio.h

#pragma once

int dustinBestTrio(int friend_nodes, int friends_from[], int friends_to[]);