Removed spaces from top-level directory names.

Spaces tend to cause annoyances in a Unix-style shell environment.
This change fixes that.

10_Blackjack/csharp/Hand.cs

@@ -0,0 +1,67 @@
+using System;
+using System.Collections.Generic;
+
+namespace Blackjack
+{
+    public class Hand
+    {
+        private readonly List<Card> _cards = new List<Card>(12);
+        private int _cachedTotal = 0;
+
+        public Card AddCard(Card card)
+        {
+            _cards.Add(card);
+            _cachedTotal = 0;
+            return card;
+        }
+
+        public void Discard(Deck deck)
+        {
+            deck.Discard(_cards);
+            _cards.Clear();
+            _cachedTotal = 0;
+        }
+
+        public void SplitHand(Hand secondHand)
+        {
+            if (Count != 2 || secondHand.Count != 0)
+                throw new InvalidOperationException();
+            secondHand.AddCard(_cards[1]);
+            _cards.RemoveAt(1);
+            _cachedTotal = 0;
+        }
+
+        public IReadOnlyList<Card> Cards => _cards;
+
+        public int Count => _cards.Count;
+
+        public bool Exists => _cards.Count > 0;
+
+        public int Total
+        {
+            get
+            {
+                if (_cachedTotal == 0)
+                {
+                    var aceCount = 0;
+                    foreach (var card in _cards)
+                    {
+                        _cachedTotal += card.Value;
+                        if (card.IsAce)
+                            aceCount++;
+                    }
+                    while (_cachedTotal > 21 && aceCount > 0)
+                    {
+                        _cachedTotal -= 10;
+                        aceCount--;
+                    }
+                }
+                return _cachedTotal;
+            }
+        }
+
+        public bool IsBlackjack => Total == 21 && Count == 2;
+
+        public bool IsBusted => Total > 21;
+    }
+}