Correct Math function for DefaultCapacity on HashTable

Add test for minimum HashTable size

Author: kamikkels

DataStructures.Tests/Hashing/HashTableTests.cs

@@ -192,6 +192,23 @@ public void Remove_TriggersResizeDown()
         Assert.That(hashTable.Capacity, Is.EqualTo(40));
     }
 
+    [Test]
+    public void Remove_TriggersResizeDown_MinimumOfDefaultCapacity()
+    {
+        var hashTable = new HashTable<int, string>(4);
+        for (var i = 1; i <= 50; i++)
+        {
+            hashTable.Add(i, $"Value{i}");
+        }
+
+        for (var i = 1; i <= 48; i++)
+        {
+            hashTable.Remove(i);
+        }
+
+        Assert.That(hashTable.Capacity, Is.EqualTo(16));
+    }
+
     [Test]
     public void ContainsValue_ReturnsFalse_WhenValueDoesNotExist()
     {

DataStructures/Hashing/HashTable.cs

@@ -286,7 +286,7 @@ public void Clear()
     public void Resize()
     {
         var newCapacity = size <= threshold / 2
-            ? Math.Min(capacity / 2, DefaultCapacity)
+            ? Math.Max(capacity / 2, DefaultCapacity)
             : capacity * 2;
         var newEntries = new Entry<TKey, TValue>[newCapacity];