Program.cs

using System;
using static System.Console;

class Program {

    static void display_user_message() => WriteLine("usage: program [-g <w> <h> <output_filename>.png] [-s dfs/bfs <input_filename>.png <output_filename>.png]");
    static void Main(string[] args) {       
        Maze maze = null;
        Solver solver = null;
        string out_filename = "";
        for (int i = 0 ; i < args.Length ; ++i) 
            switch (args[i]) {
                case "-g":
                    int width = int.Parse(args[i+1]), height = int.Parse(args[i+2]);
                    maze = new Maze(width, height);
                    out_filename = args[i+3];
                    i += 3;
                    break;
                case "-s":
                    Solver.Profile choice = args[i+1] == "dfs" ? Solver.Profile.DFS : args[i+1] == "bfs" ? Solver.Profile.BFS : Solver.Profile.Unknown;
                    maze = new Maze(args[i+2]);
                    solver = new Solver(maze, choice);
                    out_filename = args[i+3];
                    i += 3;
                    break;
                default:
                    WriteLine("invalid option: " + args[i]);                  
                    display_user_message();
                    return;
            } 

        if (maze is Maze) {
            Canvas canvas = new Canvas(maze);
            canvas.draw_the_maze(solver);
            canvas.save_image(out_filename);
            return;
        }
        
        display_user_message();                  
    }    
}