using var sr = new StreamReader("../input/day7.txt");
var lines = sr.ReadToEnd().Split("\n").Select(x => x.Trim()).ToList();
var numbers = lines.First().Split(",").Select(double.Parse).ToList();

var acc = 0.0;
var median = GetMedian(numbers.ToArray());
foreach (var num in numbers)
    acc += Math.Abs(num - median);

Console.WriteLine(acc);
acc = 0.0;
var avg = Math.Floor(numbers.Average());
foreach (var num in numbers)
{
    var n = Math.Abs(num - avg);
    acc += n * (n + 1) / 2; // Gauss formula, one of the very very few math tricks i know
}

Console.WriteLine(acc);

double GetMedian(double[] nums)
{
    var ret = 0.0;

    Array.Sort(nums);
    if (nums.Length % 2 == 0)
    {
        var firstValue = nums[(nums.Length / 2) - 1];
        var secondValue = nums[(nums.Length / 2)];
        ret = (firstValue + secondValue) / 2.0;
    }
    if (nums.Length % 2 == 1)
    {
        ret = nums[(nums.Length / 2)];
    }

    return ret;
}