04.Light The Torches

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;


class LightTheTorches
{
    static void Main()
    {
        int n = int.Parse(Console.ReadLine());
        string lightOrDark = Console.ReadLine();
        List<string> commands = new List<string>();
        do
        {
            string temp = Console.ReadLine();
            commands.Add(temp);
        } while (commands[commands.Count - 1] != "END");

        char[] rooms = new char[n];
        int lightDarkCount = 0;
        for (int i = 0; i < rooms.Length; i++)
        {
            rooms[i] = lightOrDark[lightDarkCount++];
            if (lightDarkCount == lightOrDark.Length)
            {
                lightDarkCount = 0;
            }
        }

        int fatherPosition = n / 2;
        int direction = 0;
        int roomsToSkip = 0;
        while (commands[0] != "END")
        {
            if (commands[0].Substring(0, 4) == "LEFT")
            {
                direction = -1;
                roomsToSkip = int.Parse(commands[0].Substring(5));
            }
            else
            {
                direction = 1;
                roomsToSkip = int.Parse(commands[0].Substring(6));
            }
            if (fatherPosition == 0 && direction < 0 || fatherPosition == n - 1 && direction > 0)
            {
                commands.RemoveAt(0);
                continue;
            }

            if (direction < 0)
            {
                fatherPosition = fatherPosition - ( roomsToSkip + 1);
                if (fatherPosition < 0)
                    fatherPosition = 0;
            }
            else
            {
                fatherPosition = fatherPosition + (roomsToSkip + 1);
                if (fatherPosition >= n)
                    fatherPosition = n - 1;
            }

            if (rooms[fatherPosition] == 'D')
                rooms[fatherPosition] = 'L';
            else
                rooms[fatherPosition] = 'D';

            commands.RemoveAt(0);
        }

        int countD = 0;
        foreach (var item in rooms)
        {
            if (item == 'D')
                countD++;
        }

        Console.WriteLine('D' * countD);
    }
}