Two speculators may choose to make an even swap of two properties. add a method called swap that is passed either two lists of properties (if you are writing a static method) or one portfolio (the other list is contained in the collection you are applying the method to) and two integer positions (one from each list). Swap the properties at the given positions from one list to the other, but do not change their position. For example, if speculator A swaps their property at position 2 with speculator B's property at position 0, then the swapped properties will be at position 2 for speculator A and at position 0 for speculator B. Use the ArrayList set method. Return the difference in value from your method, which may be negative depending on the direction of the swap. Add code to the main program to adequately test your new method.

add the changes to the code below !

import java.util.ArrayList; public class Activity4CAlt { public static void main(String[] args) { Portfolio jim, helen; Property property; jim = new Portfolio("Jim"); jim.add(new Property(16, 8, 160)); jim.add(new Property(24, 17, 130)); jim.add(new Property(129, 180, 35)); helen = new Portfolio("Helen"); helen.add(new Property(9, 13, 120)); helen.add(new Property(15, 15, 210)); helen.add(new Property(9, 13, 120)); jim.print(); helen.print(); jim.subdivide(0, true); jim.subdivide(2, false); helen.subdivide(0, false); property = jim.transfer(1, helen); System.out.println(property + " transferred from Jim to Helen for $" + property.value()); property = helen.transfer(3, jim); System.out.println(property + " transferred from Helen to Jim for $" + property.value()); jim.print(); helen.print(); System.out.println(" End of processing."); } } class Property { private int length, width; // both are in metres private int valuePerSqM; // value in $ per square metre public Property(int length, int width, int valuePerSqM) { this.length = length; this.width = width; this.valuePerSqM = valuePerSqM; } public int value() { return length * width * valuePerSqM; } public Property subdivide(boolean lengthwise) { Property subdivision; if (lengthwise) { subdivision = new Property(length / 2, width, valuePerSqM); length = (length + 1) / 2; } else { subdivision = new Property(length, width / 2, valuePerSqM); width = (width + 1) / 2; } return subdivision; } public String toString() { return "Property: " + length + "m long by " + width + "m wide ($" + valuePerSqM + " per square metre)"; } } class Portfolio { private Property[] list; int size; private String owner; public Portfolio(String owner) { // assume that a typical portfolio has at most 3 properties list = new Property[3]; // but it has none initially size = 0; this.owner = owner; } public void add(Property p) { if (size >= list.length) { // make the new list twice as big as the old Property[] newList = new Property[list.length * 2]; // copy the old contents to the new list System.arraycopy(list, 0, newList, 0, list.length); // replace the old list with the new one list = newList; } list[size] = p; size++; } public void print() { int totalValue; System.out.println(owner + "'s portfolio:"); totalValue = 0; for (int i = 0; i < size; i++) { System.out.println(" " + list[i]); totalValue += list[i].value(); } System.out.println("Total value: $" + totalValue); } public void subdivide(int position, boolean lengthwise) { Property toSubdivide; Property subdivision; toSubdivide = list[position]; subdivision = toSubdivide.subdivide(lengthwise); add(subdivision); } public Property transfer(int position, Portfolio buyer) { Property toTransfer; toTransfer = list[position]; remove(position); buyer.add(toTransfer); return toTransfer; } private void remove(int position) { for (int i = position + 1; i < size; i++) { list[i - 1] = list[i]; } size--; } }