Please help with letterToNum, squares, and countWords

public class HapExercises f Returns a map from every lower case letter to the number corresponding to that letter, where ' a ' is 1 , ' b ' is 2, ' c ' is 3,. ' 2 ' is 26. public static MapcCharacter, Integers LetterToNum() \& ceturnini. /** Returns a map from the integers in the list to their squares. For example, if the input list * is [1,3,6,7], the returned mop goes from 1 to 1,3 to 9,6 to 36 , and 7 to 49 . / public static Map squares(List nuns) f return nuzl; \} /** Returns a map of the counts of all words that appear in a list of words. */ public static Map countWords(List words) f return null; \}. f