Chapter 19.9, Problem 40SC

Explanation of Solution

Given Program:

//include the header file

import java.util.List;

import java.util.Map;

import java.util.Optional;

 import java.util.Set;

 import java.util.stream.Stream;

 import java.util.stream.Collectors;

//definition of "GroupDemo" class

public class GroupDemo

{

    //definition of main method

    public static void main(String[] args)

    {

        //set the strings to the variable

String[] words = ("Mary had a little lamb").split(" ");

        //group the words

        Map<String, List<String>> groups = Stream...