public IList <IInstruction> Parse(string input)
{
List <IInstruction> instructions = new List <IInstruction>();
//e.g. LMLMLMLMM
foreach (char c in input.ToUpper())
{
IInstruction newInstruction = new NullInstruction();;
switch (c)
{
case 'L':
newInstruction = new LeftInstruction();
break;
case 'M':
newInstruction = new MoveInstruction();
break;
case 'R':
newInstruction = new RightInstruction();
break;
default:
break;
}
instructions.Add(newInstruction);
}
return(instructions);
}
public void Should_Change_Orientation_Counterclockwise_When_LeftInstruction_Moves()
{
ShipPosition position = new ShipPosition(5, 5, Orientation.West);
LeftInstruction instruction = new LeftInstruction(topRight, bottomLeft);
//test
ShipPosition actual = instruction.Move(position);
//assert
Assert.AreEqual(Orientation.South, actual.Orientation, "orientation not correct");
Assert.AreEqual(position.X, actual.X, "ship should not have moved x corordinate");
Assert.AreEqual(position.Y, actual.Y, "ship should not have moved y corordinate");
Assert.AreEqual(false, actual.Lost, "ship should not be lost");
}
// Replace scan loop [<] and [>] with single instruction
public List <InstructionBase> OptimizeScanLoop(List <InstructionBase> instructions)
{
List <InstructionBase> optimized = new List <InstructionBase>();
for (int i = 0; i < instructions.Count; i++)
{
InstructionBase instruction = instructions[i];
bool optimizationFound = false;
if (instruction is OpenInstruction && i < instructions.Count - 2)
{
LeftInstruction left = instructions[i + 1] as LeftInstruction;
if (left?.X == 1 && instructions[i + 2] is CloseInstruction)
{
Debug.WriteLine("Left scan loop found");
optimizationFound = true;
optimized.Add(new ScanLeftInstruction());
i += 2;
}
else
{
RightInstruction right = instructions[i + 1] as RightInstruction;
if (right?.X == 1 && instructions[i + 2] is CloseInstruction)
{
Debug.WriteLine("Right scan loop found");
optimizationFound = true;
optimized.Add(new ScanRightInstruction());
i += 2;
}
}
}
if (!optimizationFound)
{
optimized.Add(instruction);
}
}
return(optimized);
}
