/// <param name="w">Plateau's width</param>
/// <param name="h">Plateau's height</param>
public Rover(int x, int y, Utils.Orientation orientation, RoverCommands nav, int w, int h)
{
this.Commands = nav ?? throw new ArgumentNullException(nameof(nav));
this.w = w;
this.h = h;
this.StartingState = new RoverState(x, y, orientation);
this.CurrentState = this.StartingState.Clone();
StateHistory.Add(this.CurrentState);
}
/// <summary>Parse a string of L R and M into a list of commands</summary>
/// <returns>I like the TryParse pattern, I think it fits here</returns>
public static bool TryParse(string input, out RoverCommands nav)
{
nav = default;
if (string.IsNullOrWhiteSpace(input))
{
throw new ArgumentNullException(input);
}
var lst = new List <Utils.Command>();
foreach (var chr in input.Trim().ToUpperInvariant().ToCharArray())
{
switch (chr)
{
case 'L':
lst.Add(Utils.Command.Left);
break;
case 'R':
lst.Add(Utils.Command.Right);
break;
case 'M':
lst.Add(Utils.Command.Move);
break;
default:
return(false);
}
}
if (lst.Count == 0)
{
return(false);
}
nav = new RoverCommands(lst);
return(true);
}
/// <summary>
/// Split the input into lines and process according to spec
/// </summary>
/// <returns>grid width and height and rovers preloaded with nav paths</returns>
/// <remarks>
/// Test Input:
/// 5 5
/// 1 2 N
/// LMLMLMLMM
/// 3 3 E
/// MMRMMRMRRM
/// Expected Output:
/// 1 3 N
/// 5 1 E
/// </remarks>
public static (int gridWidth, int gridHeight, Rovers rovers) ProcessInput(string text)
{
if (string.IsNullOrWhiteSpace(text))
{
throw new ArgumentNullException(nameof(text));
}
var lines = text.Split(new[] { "\r\n", "\r", "\n" }, StringSplitOptions.RemoveEmptyEntries);
if (lines.Length == 0)
{
throw new ArgumentException("invalid format, no lines found", nameof(text));
}
var splits = lines[0].Split(new[] { ' ' }, StringSplitOptions.RemoveEmptyEntries);
if (splits.Length != 2)
{
throw new Exception("invalid format - first line, should have 2 numbers");
}
if (!int.TryParse(splits[0], out int w) || w <= 0)
{
throw new Exception("invalid format - first line, should have 2 numbers, first part was not a >0 integer");
}
if (!int.TryParse(splits[1], out int h) || h <= 0)
{
throw new Exception("invalid format - first line, should have 2 numbers, second part was not a >0 integer");
}
if (lines.Length > 2)
{
var lst = new List <Rover>();
for (int i = 1; i < lines.Length; i += 2)
{
if (char.IsDigit(lines[i][0]))
{
//current line is the starting coordinate of a rover since it's starting with a number
splits = lines[i].Split(' ');
if (splits.Length < 3 ||
!int.TryParse(splits[0], out int x) ||
!int.TryParse(splits[1], out int y) ||
!Utils.OrientationTryParse(splits[2], out Utils.Orientation orientation))
{
throw new Exception("invalid format line: " + i);
}
if (x < 0 || x > w || y < 0 || y > h)
{
throw new Exception("invalid position, outside the bounds");
}
if (i < lines.Length - 1)
{
//nav points must be on the next line
if (!RoverCommands.TryParse(lines[i + 1], out RoverCommands nav))
{
throw new Exception("invalid format line: " + i + 1);
}
lst.Add(new Rover(x, y, orientation, nav, w, h));
}
}
}
return(w, h, new Rovers(lst));
}
return(w, h, null);
}
