Task $3$: MapExercises

MapExercises.java has $3$ different methods for you to complete:

letterToNum: This method returns a map from every lower case letter to the number corresponding to its ordering in the alphabet, where $$a$$ corresponds to $1$ and $$z$$ corresponds to $26.$

squares: This method takes a list List nums and returns a map from the integers in the list to their squares. If the given list is empty, it should return an empty map.

countWords: This method takes a list List words and returns a map from words in the list to the number of times they appear. If the given list is empty, it should return an empty map.

For this part, you can import TreeMap.