--- Day 10: Adapter Array ---

#include <iostream>
#include <string>
#include <vector>
#include <array>
#include <algorithm>

std::vector<int> adapters;

int CalculateDifference(int outlet, int adapter)
{
    int diff = adapter - outlet;
    return diff;
}

long long FindArrangements(std::string output = "0, ")
{
    //Part 1
    int diff = 0;
    int outlet = 0;
    std::array<int, 3> numDiffs = { 0, 0, 0 };
    for (unsigned int i = 1; i < adapters.size(); i++)
    {
        diff = CalculateDifference(outlet, adapters[i]);

        numDiffs[diff - 1]++;
        outlet += diff;
        output += std::to_string(outlet) + ", ";
    }

    output += "[ ";
    for (unsigned int i = 0; i < 3; i++)
        output += std::to_string(numDiffs[i]) + " ";

    output += "]";

    std::cout << output << std::endl;

    //Part 2 - Result too low
    std::vector<long long> path(adapters.size(), 0);
    path[path.size() - 1] = 1;
    for(int i = path.size() - 1; i >= 0; i--)
    {
        for (int j = i + 1; j < adapters.size(); j++)
        {
            if (adapters[j] - adapters[i] <= 3)
                path[i] += path[j];
            else
                break;
        }
    }

    std::cout << "Arrangements: " << path[0] << std::endl;

    return 0;
}

int main()
{
    int largest = 0;
    std::string text;
    while (getline(std::cin, text))
    {
        int a = atoi(text.c_str());
        if (a > largest)
            largest = a;

        adapters.push_back(a);
    }

    adapters.push_back(0);
    adapters.push_back(largest + 3);
    std::sort(adapters.begin(), adapters.end());

    return FindArrangements();
}