Notes about Dictionary Classes

Class Dictionary<K,V>
- Based on a hash table
- Requires that the keys in type K can be compared by an Equals operation
- Key values should not be mutated
- The efficiency of class dictionary relies on a good hash function for the key type K
  - Consider overriding the method GetHashCode in class K
- A dictionary is enumerated in terms of the struct KeyValuePair<K,V>
Class SortedDictionary<K,V>
- Based on a binary search tree
- Requires an IComparer for keys of type K - for ordering purposes
  - Provided when a sorted dictionary is constructed
Class SortedList<K,V>
- Based on a sorted collection of key/value pairs
  - A resizeable array
- Requires an IComparer for keys, just like SortedDictionary<K,V>.
- Requires less memory than SortedDictionary<K,V>.