using System;
using System.Collections.Generic;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace Lines
{
    class Wave
    {
        private int[][] mas;
        private Point start;
        private Point finish;
        private Size size;
        private List<Point> short_path = new List<Point>();
        public Wave(int[][] mas_1, Point start_1, Point finish_1)
        {
            mas = mas_1;
            start = finish_1;
            finish = start_1;
            size = new Size(mas.Length, mas.First().Length);
            MessageBox.Show(mas[start.X][start.Y].ToString());
        }
        public void SetParameters(int[][] mas_1, Point start_1, Point finish_1)
        {
            mas = mas_1;
            start = finish_1;
            finish = start_1;
            size = new Size(mas.Length, mas[0].Length);
        }
        public Point[] GetPath()
        {
            for (int i = -1; NextStep(i); ++i) ;
            return short_path.ToArray();
        }
        private bool NextStep(int step)
        {
            for (int i = 0; i != size.Width; ++i)
            {
                for (int j = 0; j != size.Height; ++j)
                {
                    if (mas[i][j] == -2)
                    {
                        short_path.Add(new Point(i, j));
                        for (; step != -3; --step)
                        {
                            if (short_path.Last().X != 0)
                                if (mas[short_path.Last().X - 1][short_path.Last().Y] == step)
                                    short_path.Add(new Point(short_path.Last().X - 1, short_path.Last().Y));
                            if (short_path.Last().Y != size.Width - 1)
                                if (mas[short_path.Last().X][short_path.Last().Y + 1] == step)
                                    short_path.Add(new Point(short_path.Last().X, short_path.Last().Y + 1));
                            if (short_path.Last().X != size.Height - 1)
                                if (mas[short_path.Last().X + 1][short_path.Last().Y] == step)
                                    short_path.Add(new Point(short_path.Last().X + 1, short_path.Last().Y));
                            if (short_path.Last().Y != 0)
                                if (mas[short_path.Last().X][short_path.Last().Y - 1] == step)
                                    short_path.Add(new Point(short_path.Last().X, short_path.Last().Y - 1));
                        }
                        return false;
                    }
                    if (mas[i][j] == step)
                    {
                        if (i != 0)
                            if (mas[i - 1][j] == 0)
                                mas[i - 1][j] = step + 1;
                        if (j != size.Width - 1)
                            if (mas[i][j + 1] == 0)
                                mas[i][j + 1] = step + 1;
                        if (i != size.Height - 1)
                            if (mas[i + 1][j] == 0)
                                mas[i + 1][j] = step + 1;
                        if (j != 0)
                            if (mas[i][j - 1] == 0)
                                mas[i][j - 1] = step + 1;
                    }
                }
            }
            return false;
        }
    }
}