2024day20straightForward

public static class Day20
{
    private static string[] Grid;
    private static int[] d = [0, 1, 2, 3];
    private static int[] dx = [1, 0, -1, 0];
    private static int[] dy = [0, 1, 0, -1];
    private static (int x, int y) Start, Ende;

    public static int Solve1(string input) => Solve(input, 2);

    public static int Solve2(string input) => Solve(input, 20);

    public static int Solve(string input, int cheatSteps)
    {
        Grid = input.Split(Environment.NewLine);
        ScanGrid();
        (int x, int y)[] path = BFS(Start, Nexts, includeWhen, skipWhen, exitWhen).ToArray;
        List<int> result = new();
        for (int i = 0; i < path.Length - 3; i++)
        {
            for (int j = i + 3; j < path.Length; j++)
            {
                int diff = Math.Abs(path(j).x - path(i).x) + Math.Abs(path(j).y - path(i).y);
                if (diff <= cheatSteps)
                    result.Add(j - i - diff);
            }
        }
        return result.AsEnumerable().Count(i => i > 99);
    }
    private static void ScanGrid()
    {
        for (int y = 0; y < Grid.Length; y++)
        {
            for (int x = 0; x < Grid[0].Length; x++)
            {
                if (Grid[y][x] == 'S')
                    Start = (x, y);
                if (Grid[y][x] == 'E')
                    Ende = (x, y);
            }
        }
    }
    private static (int x, int y)[] Nexts((int x, int y) p) => d.Select(i => (p.x + dx[i], p.y + dy[i])).Where(q => CheckGridBound(q, Grid, '#')).ToArray;

    private static bool includeWhen((int x, int y) _step) => true;

    private static bool skipWhen((int x, int y) _step) => false;

    private static bool exitWhen((int x, int y) _step) => return _step.Equals(Ende);
}