Level Data

using System.Collections.Generic;

[System.Serializable]
public class LevelData
{
    public int GridXSize;
    public int GridYSize;
    public List<ArrowData> Arrows = new List<ArrowData>();

    public bool CanSolveLevel()
    {
        if (Arrows.Count == 0) return true;

        int totalCells = GridXSize * GridYSize;
        int[] board = new int[totalCells];
        System.Array.Fill(board, -1);

        for (int i = 0; i < Arrows.Count; i++)
        {
            foreach (int idx in Arrows[i].Indices)
                board[idx] = i;
        }

        bool[] removed = new bool[Arrows.Count];
        int removedCount = 0;
        bool changed;

        do
        {
            changed = false;
            for (int i = 0; i < Arrows.Count; i++)
            {
                if (removed[i]) continue;

                if (CanExit(Arrows[i], board))
                {
                    foreach (int idx in Arrows[i].Indices)
                        board[idx] = -1;

                    removed[i] = true;
                    removedCount++;
                    changed = true;
                }
            }
        } while (changed);

        return removedCount == Arrows.Count;
    }

    private bool CanExit(ArrowData arrow, int[] board)
    {
        int headIdx = arrow.Indices[0];
        int neckIdx = arrow.Indices[1];

        int hx = headIdx % GridXSize;
        int hy = headIdx / GridXSize;
        int nx = neckIdx % GridXSize;
        int ny = neckIdx / GridXSize;

        int dx = hx - nx;
        int dy = hy - ny;

        int cx = hx + dx;
        int cy = hy + dy;

        while (cx >= 0 && cx < GridXSize && cy >= 0 && cy < GridYSize)
        {
            int checkIdx = cy * GridXSize + cx;
            if (board[checkIdx] != -1) return false;
            cx += dx;
            cy += dy;
        }

        return true;
    }
}

[System.Serializable]
public class ArrowData
{
    public List<int> Indices = new();
    public int ColorIndex = 0;
}