AdventOfCode/AdventOfCode.Solutions/2022/Day 05/CraneWork.cs

namespace AdventOfCode.Solutions._2022.Day_05
{
    internal class CraneWork
    {
        private List<Stack<char>> containerStacks = new List<Stack<char>>();

        internal void ReadInitialContainerArrangement(string[] data)
        {
            // get all the existing stacks
            string stackNumbers = data[data.Length - 1];
            string[] containerStacksWithoutNumbser = data.Take(data.Length - 1).ToArray();
            for (int stackIndex = 0; stackIndex < stackNumbers.Length; stackIndex++)
            {
                if (stackNumbers[stackIndex] == ' ')
                {
                    continue;
                }

                Stack<char> stack = new Stack<char>();
                for (int containerIndex = containerStacksWithoutNumbser.Length - 1; containerIndex >= 0; containerIndex--)
                {
                    char container = containerStacksWithoutNumbser[containerIndex][stackIndex];
                    if (container != ' ')
                    {
                        stack.Push(container);
                    }
                    else
                    {
                        break;
                    }
                }

                containerStacks.Add(stack);
            }
        }

        internal void DoCraneWork(string craneInstruction, bool is9000Crane = true)
        {
            string[] instructions = craneInstruction.Split(' ');
            int numberToMove = Convert.ToInt32(instructions[1]);

            // remove one because zero based index
            int fromContainerStackIndex = Convert.ToInt32(instructions[3]) - 1;
            int toContainerStackIndex = Convert.ToInt32(instructions[5]) - 1;
            Stack<char> storage = new Stack<char>();

            for (int toMove = numberToMove; toMove > 0; toMove--)
            {
                if (is9000Crane)
                {
                    containerStacks[toContainerStackIndex].Push(containerStacks[fromContainerStackIndex].Pop());
                }
                else
                {
                    // make a stack to store the containers in order
                    storage.Push(containerStacks[fromContainerStackIndex].Pop());
                }
            }

            if (!is9000Crane)
            {
                // move the stored conainers to the new pile
                for (int toMove = numberToMove; toMove > 0; toMove--)
                {
                    containerStacks[toContainerStackIndex].Push(storage.Pop());
                }
            }
        }

        internal string GetTopContainers()
        {
            string result = string.Empty;
            foreach (char topContainer in containerStacks.Select(s => s.Peek()))
            {
                result += topContainer;
            }

            return result;
        }
    }
}