Chapter 16, Problem 4PE

Program Plan Intro

A method “size()”

Program plan:

• In a file “ListIterator.java”, create an interface “ListIterator”,
  • Declare the method “next()” that moves the iterator past the next element.
  • Declare the method “hasNext()” that check if there is an element after the iterator position.
  • Declare the method “add()”  that adds an element before the position of the iterator and moves the iterator past the added element.
  • Declare the method “remove()” that removes the last traversed element.
  • Declare the method “set()” to set the last traversed element to a previous value.
• In a file “LinkedList.java”, import the package and create a class “LinkedList”,
  • Declare the object variable.
  • Define the constructor to create an empty linked list.
  • Define the method “size()” to compute the linked list size,
    • Initialize the variable that holds size.
    • Assign the first reference to the current node.
    • Execute a loop,
      • Increment the size.
      • Assign the next of the current node to the current node.
    • Return the linked list size.
      • • Define the method “getFirst()” that returns the first element in the linked list.
        • Define the method “removeFirst()” to remove the first element in the linked list.
        • Define the method “addFirst()” that adds an element to the front of the linked list,
        • • Create a new node.
          • Assign the value to the new node.
          • Assign the first element to the next pointer of new node.
          • Assign new node to the first position.
        • Define the method “listIterator()” of type “ListIterator”, that returns an iterator for iterating through the list.
        • Create a class “Node”,
        • • Declare the object variable for “Object”, and “Node”.
        • Create a class “LinkedListIterator”,
        • • Declare the necessary object variables.
          • Define the constructor to create an iterator that points to the front of the linked list.
          • Define the method “next()”,
            • If there is no next element then throws an exception.
            • Assign the position to the front of the linked list.
            • Check if position is null, set the first element to the position.
            • Otherwise, set the next position to the current position.
            • Returns the value.
              • Define the method “hasNext()” that check whether there is next element,
                • Check if position is null,
                  • Returns true if first reference is not null.
                • Otherwise,
                  • Returns true, if the next reference of the position is not null.
              • Define the method “add()”,
                • If position is null, call the method “addFirst()”.
                  • Set the first to the position.
                • Otherwise, create a new node.
                  • Assign the element to the new node.
                  • Set the next position to the next pointer of the new node.
                  • Set the new node value to the next position.
                  • Set the new node as the position.
                • Set the Boolean value as false.
              • Define the method “remove()”,
                • Check if there is no next element, throws an exception.
                • If position is same as the first, calls the method “removeFirst()”.
                • Otherwise, set the next position to the previous position.
                • Set the previous to the positions.
                • St the Boolean value to false.
              • Define the method “set()”,
                • If there is no next element, throw an exception.
                • Set the value to the position.
• In a file “SizeTest.java”, create a class “SizeTest”,
  • Define the “main()” method.
    • Create the “LinkedList” object.
    • Call the method “addFirst()” to add “Tommy” to the front of the linked list.
    • Call the method “addFirst()” to add “Roma” to the font of the linked list.
    • Call the method “addFirst()” to add “Harris” to the font of the linked list.
    • Call the method “addFirst()” to add “David” to the font of the linked list.
    • Assign the value returned from the method “listIterator()” calling by  LinkedList object.
    • Call the method “next()”.
    • Call the method “next()”.
    • Call the method “remove()”.
    • Call the method “next()”.
    • Call the method “remove()”.
    • Call the method “add()” to add “John” to the linked list.
    • Call the method “next()”.
    • Call the method “set()”.
    • Call the method “removeFirst()”.
    • Assign the value returned from the method “listIterator()”.
    • Execute a loop,
      • Print the actual output.
        • • • • Print the new line.
              • Print the expected output.
              • Print the actual size of the linked list.
              • Print the expected size of the linked list.