Count the number of increments traversed while opening a combination lock. Challenge link: http://www.reddit.com/r/dailyprogrammer/comments/1v4cjd/011314_challenge_148_easy_combination_lock/

CountIncrementTraversals.cs

using System;

class Program
{
	static void Main(string[] args)
	{
		#region Argument Count / Data Type Validation
		// Check for valid number of command line arguments.
		if (args == null || args.Length != 4)
		{
			Console.WriteLine("Pass 4 command line arguments. The 1st should be the count of numbers on the face of the lock. The next three should be the combination.");
			Console.ReadKey();
			return;
		}

		// Ensure all command line arguments can be parsed into integers.
		foreach (string arg in args)
		{
			int trash;
			bool isAnInteger = Int32.TryParse(arg, out trash);

			if (!isAnInteger)
			{
				Console.WriteLine("All command line arguments must be integers.");
				Console.ReadKey();
				return;
			}
		}
		#endregion

		#region Gather Command Line Arguments
		int countOfNumbersOnLock = Convert.ToInt32(args[0]);
		int firstNumberInCombination = Convert.ToInt32(args[1]);
		int secondNumberInCombination = Convert.ToInt32(args[2]);
		int thirdNumberInCombination = Convert.ToInt32(args[3]);
		#endregion

		#region Argument Range Validation
		// Validate the count of numbers on the lock is within the range 0 to 255.
		if (countOfNumbersOnLock < 0 || countOfNumbersOnLock > 255)
		{
			Console.WriteLine("The first command line argument, the count of numbers on the face of the lock, must be between 0 and 255.");
			Console.ReadKey();
			return;
		}

		// Validate the combination falls within possible values.
		if (firstNumberInCombination < 0 || firstNumberInCombination > (countOfNumbersOnLock - 1)
			|| secondNumberInCombination < 0 || secondNumberInCombination > (countOfNumbersOnLock - 1)
			|| thirdNumberInCombination < 0 || secondNumberInCombination > (countOfNumbersOnLock - 1))
		{
			Console.WriteLine("The numbers in the combination must be positive integers that are less than or equal to the count of numbers on the face of the lock minus one.");
			Console.ReadKey();
			return;
		}
		#endregion

		#region Calculation
		// Calculate increments traversed during each spin.
		int incrementsDuringFirstSpin = countOfNumbersOnLock * 2;
		int incrementsDuringSecondSpin = firstNumberInCombination;
		int incrementsDuringThirdSpin = countOfNumbersOnLock;
		int incrementsDuringFourthSpin = ((firstNumberInCombination - secondNumberInCombination) + countOfNumbersOnLock) % countOfNumbersOnLock;
		int incrementsDuringFifthSpin = (thirdNumberInCombination == secondNumberInCombination)
			? countOfNumbersOnLock
			: ((thirdNumberInCombination - secondNumberInCombination) + countOfNumbersOnLock) % countOfNumbersOnLock;

		// Total the increments traversed for all spins.
		int totalNumberOfIncrements = incrementsDuringFirstSpin
			+ incrementsDuringSecondSpin
			+ incrementsDuringThirdSpin
			+ incrementsDuringFourthSpin
			+ incrementsDuringFifthSpin;
		#endregion

		#region Display Results
		// Display command line arguments.
		foreach (string arg in args)
			Console.Write(arg + " ");
		Console.WriteLine();

		// Display result.
		Console.Write(totalNumberOfIncrements);
		Console.ReadKey();
		#endregion
	}
}