Fix max/min for ordered hash tables

Author: justcoding121

src/Advanced.Algorithms/DataStructures/Dictionary/OrderedDictionary.cs

@@ -154,7 +154,7 @@ public KeyValuePair<K, V> NextLower(K key)
         /// </summary>
         public KeyValuePair<K, V> Max()
         {
-            var max = binarySearchTree.Min();
+            var max = binarySearchTree.Max();
             return max.Equals(default(OrderedKeyValuePair<K, V>)) ? default(KeyValuePair<K, V>)
                 : max.ToKeyValuePair();
         }

src/Advanced.Algorithms/DataStructures/HashSet/OrderedHashSet.cs

@@ -120,15 +120,15 @@ public T NextLower(T value)
         /// </summary>
         public T Max()
         {
-            return binarySearchTree.Min();
+            return binarySearchTree.Max();
         }
 
         /// <summary>
         /// Time complexity: O(log(n)).
         /// </summary>
         public T Min()
         {
-            return binarySearchTree.Max();
+            return binarySearchTree.Min();
         }
 
         /// <summary>