Chapter 11.3, Problem 20SCP

Explanation of Solution

Program:

//define the static function

public static void mystery(Map<String, String> m) {

    //create a new set

    Set<String> s= new TreeSet<>();

    //loop initialized to add and remove the values

    for(String key : m.keySet()) {

        //condition initialized to compare the key value

        if(!m.get(key).equals(key)) {

            //add the element

            s.add(m.get(key));

    }else {

        //remove the element

        s...