matrix parking lot

using System;
using System.Collections.Generic;
using System.Linq;

    public class TheParkingSystem
    {
        public static void Main()
        {
            var parking = new Dictionary<int, HashSet<int>>();
            var size = Console.ReadLine()
                .Split(new[] { ' ' }, StringSplitOptions.RemoveEmptyEntries)
                .Select(int.Parse)
                .ToArray();
            var cols = size[1];

            while (true)
            {
                string input = Console.ReadLine().Trim();

                if (input == "stop")
                {
                    break;
                }

                var args = input.Split(new[] { ' ' }, StringSplitOptions.RemoveEmptyEntries)
                    .Select(int.Parse)
                    .ToArray();
                var entryRow = args[0];
                var targetRow = args[1];
                var targetCol = args[2];

                if (!IsOccupiedSpot(parking, targetRow, targetCol))
                {
                    TakeParkingSpot(parking, targetRow, targetCol);
                    Console.WriteLine(CalcDistanceToParkingSpot(entryRow, targetRow, targetCol));
                }
                else
                {
                    targetCol = TryFindEmptySpot(parking[targetRow], targetCol, cols);
                    if (targetCol == 0)
                    {
                        Console.WriteLine($"Row {targetRow} full");
                    }
                    else
                    {
                        TakeParkingSpot(parking, targetRow, targetCol);
                        Console.WriteLine(CalcDistanceToParkingSpot(entryRow, targetRow, targetCol));
                    }
                }
            }
        }

        private static int TryFindEmptySpot(HashSet<int> parkingRow, int targetCol, int cols)
        {
            var targetColFound = 0;
            int minDistance = int.MaxValue;

            if (parkingRow.Count == cols - 1)
            {
                return targetColFound;
            }

            for (int col = 1; col < cols; col++)
            {
                var currentDistance = Math.Abs(targetCol - col);

                if (!parkingRow.Contains(col) && currentDistance < minDistance)
                {
                    targetColFound = col;
                    minDistance = currentDistance;
                }
            }

            return targetColFound;
        }

        private static long CalcDistanceToParkingSpot(int entryRow, int targetRow, int targetCol)
        {
            return Math.Abs(targetRow - entryRow) + targetCol + 1;
        }

        private static void TakeParkingSpot(Dictionary<int, HashSet<int>> parking, int row, int col)
        {
            if (!parking.ContainsKey(row))
            {
                parking[row] = new HashSet<int>();
            }

            parking[row].Add(col);
        }

        private static bool IsOccupiedSpot(Dictionary<int, HashSet<int>> parking, int row, int col)
        {
            return parking.ContainsKey(row) && parking[row].Contains(col);
        }
    }