Complete the implementation of the LinkedStack class by providing the definitions for the peek, size, isEmpty, and toString methods.

Import the HashMap and Map classes from the java.util package. Within the main method, a sentence is declared as a string variable and assigned the value "This is a test sentence with no repeating words". Split the sentence into words using the split method and store the result in a String array called "words". Create a new Map called "wordFrequency" that stores each word as a key and the frequency of the word in the sentence as the corresponding value using the HashMap implementation. Use a for loop to iterate through each word in the "words" array. Within the for loop, the code should use the containsKey method to check if the word is already in the Map. If the word is already in the Map, its frequency should be incremented by 1. Use the put method to add the word as the key and the incremented frequency as the value to increment it. If the word is not in the map, add it as a new key with a frequency of 1 as its value. Outside of the for loop, use System.out.println to…

I have an ArrayList and I want to sort it by increasing string length. The ArrayList class has a method sort(Comparator comp). Give a class that implements the Comparator interface that I can use to sort my ArrayList.

implemente The Peek method  by calling the Item method with the index variable as the argument. The Clear method simply calls an identical method in the ArrayList class. The Count property is written as a read-only property since we don’t want to accidentally change the number of items on the stack