public class ConsCell { private int head; private ConsCell tail; public ConsCell(int h, ConsCell t) { head = h; tail = t; } public int getHead() { return head; } public ConsCell getTail() { return tail; } public void setTail(ConsCell t) { tail = t; } }

public class IntList { private ConsCell start; public IntList (ConsCell s) { start = s; } public IntList cons(int h) { return new IntList(new ConsCell(h, start)); } public int length() { int len = 0; ConsCell cell = start; while (cell != null) { len++; cell = cell.getTail(); } return len; } public void print() { System.out.print("["); ConsCell a = start; while(a != null) { System.out.print(a.getHead()); a = a.getTail(); if(a != null) System.out.print(","); } System.out.println("]"); } //exercise 5 public IntList reverse() { IntList Reverselist = new IntList(null); ConsCell begin = start; while (begin != null) { Reverselist = Reverselist.cons(begin.getHead()); begin = begin.getTail(); } return Reverselist; } }

public class Driver { public static void main (String[] args) { IntList a = new IntList (null); IntList b = a.cons(2); IntList c = b.cons(1); IntList d = c.reverse(); int x = a.length() + b.length() + c.length(); a.print(); b.print(); c.print(); d.print(); System.out.println(x); } }

Exercise 3 Add an equals instance method to the IntList class, so that x.equals(y) returns true if the IntList x and the IntList y have exactly the same integers in the same order and returns false otherwise. It should be true that x.equals(y) is always equivalent to y.equals(x). It should also be true that if x==y then x.equals (y), although the reverse should not necessarily be true