LinkedList

Semester 3/Assignments/LinkedList/src/linkedlist/MyList.java

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+/*
+ * Click nbfs://nbhost/SystemFileSystem/Templates/Licenses/license-default.txt to change this license
+ * Click nbfs://nbhost/SystemFileSystem/Templates/Classes/Class.java to edit this template
+ */
+package linkedlist;
+
+import java.util.LinkedList;
+
+/**
+ *
+ * @author caleb
+ */
+public class MyList<E> {
+
+    private Node<E> head;
+
+    class Node<E> {
+
+        E e; // Data than can be anything
+        Node<E> link; // Address of another node
+
+    }
+
+    public boolean add(E e)
+    {
+        Node<E> newNode = new Node<E>();
+        newNode.e = e;
+        
+        if (head == null) {
+            head = newNode;
+        } else {
+            Node<E> p = head;
+            Node<E> pTrail = head;
+            while (p != null) {
+                pTrail = p;
+                p = p.link;
+            }
+            pTrail.link = newNode;
+        }
+        return true;
+    }
+    
+ public boolean add(E e, int index) {
+        Node<E> newNode = new Node<E>();
+        newNode.e = e;//copy data
+
+        //Check index location
+        if (index < 0 || index > size()) {
+            throw new IndexOutOfBoundsException();
+        }
+
+        //Case 1: list is empty and the index is zero
+        if (size() == 0 && index == 0) {
+            head = newNode;
+        } //Case 2: Add at front
+        else if (index == 0) {
+            //Connect newNode with the first node
+            newNode.link = head;
+            //Make head point to new node
+            head = newNode;
+        }
+        //Case 3: Add in middle
+        else if (index < size())
+        {
+            Node<E> p = head;
+            for (int i = 0; i < index - 1; ++i)
+            {
+                p = p.link;//advance the p
+            }
+            //Point link of new node to next node
+            newNode.link = p.link;
+            //make previous node link point to new node
+            p.link = newNode;
+        }
+        //Case 4: Add at end of list
+        else {
+            add(e);
+        }
+        return true;
+    }
+
+    @Override
+    public String toString()
+    {
+        String s = "";
+        Node<E> p = head;
+        while (p != null) {
+            s += p.e.toString() + " ";
+            p = p.link;
+        }
+        return "MyList{" + s + "}";
+    }
+    
+        public int size()
+    {
+        int count = 0;
+        Node<E> p = head;
+        while (p != null) {
+            ++count;
+            p = p.link;
+        }
+        return count;
+    }
+        
+        public E removeAt(int index) {
+            if (index < 0 || index >= size())
+                throw new IndexOutOfBoundsException();
+            if (size() == 0) 
+                throw new RuntimeException("Empty List");
+            E removedE = null;
+            if (index == 0) {
+                // remove the front
+                removedE = head.e;
+                Node<E> p  = head;
+                head = head.link;
+                p.link = null;
+            }
+            if (index > 0 && index < size()) { // remove middle
+                Node<E> p = head;
+                for (int i = 0; i < index - 1; ++i) {
+                    p = head.link;
+                }
+                removedE = p.link.e;
+                p.link = p.link.link;
+            } else { // Remove at end
+                Node<E> p = head;
+                for (int i = 0; i < index -1; ++i) {
+                    p = p.link;
+                    removedE = p.link.e;
+                    p.link = null;
+                }
+            }
+            return removedE;
+        }
+
+    public static void main(String[] args)
+    {
+        LinkedList<Integer> linkedList = new LinkedList<>();
+        MyList<Integer> ml = new MyList<>();
+        ml.add(10);
+        ml.add(20);
+        ml.add(30);
+        ml.add(5, 0);
+        ml.add(25, 3);
+        ml.add(40, 5);
+        System.out.println("removing " + ml.removeAt(2) + "...");
+        System.out.println(ml);
+        System.out.println(ml.size());
+    }
+}