In this commit I have:

Added JavaDoc to every package except for "heaps"

data_structures/BinaryTree.java

@@ -1,11 +1,35 @@
-//A binary tree is a data structure in which an element has two successors(children)
-//The left child is usually smaller than the parent, and the right child is usually bigger
+/**
+ * This entire class is used to build a Binary Tree data structure.
+ * There is the Node Class and the Tree Class, both explained below.
+ * 
+ * @author Unknown
+ *
+ */
+
+
+/**
+ * This class implements the nodes that will go on the Binary Tree.
+ * They consist of the data in them, the node to the left, the node
+ * to the right, and the parent from which they came from.
+ * 
+ * @author Unknown
+ *
+ */
 class Node{
+	/** Data for the node */
 	public int data;
+	/** The Node to the left of this one */
 	public Node left;
+	/** The Node to the right of this one */
 	public Node right;
+	/** The parent of this node */
 	public Node parent;
 
+	/**
+	 * Constructor of Node
+	 * 
+	 * @param value Value to put in the node
+	 */
 	public Node(int value){
 		data = value;
 		left = null;
@@ -14,13 +38,33 @@ class Node{
 	}
 }
 
+
+/**
+ * A binary tree is a data structure in which an element
+ * has two successors(children). The left child is usually
+ * smaller than the parent, and the right child is usually
+ * bigger.
+ * 
+ * @author Unknown
+ *
+ */
 class Tree{
+	/** The root of the Binary Tree */
 	private Node root;
 
+	/**
+	 * Constructor
+	 */
 	public Tree(){
 		root = null;
 	}
-	//Returns the node if it finds it, otherwise returns the parent
+	
+	/**
+	 * Method to find a Node with a certain value
+	 * 
+	 * @param key Value being looked for
+	 * @return The node if it finds it, otherwise returns the parent
+	 */
 	public Node find(int key){
 		Node current = root;
 		Node last = root;
@@ -37,7 +81,11 @@ class Tree{
 		return last;
 	}
 
-	//Inserts the given value
+	/**
+	 * Inserts certain value into the Binary Tree
+	 * 
+	 * @param value Value to be inserted
+	 */
 	public void put(int value){
 		Node newNode = new Node(value);
 		if(root == null)
@@ -60,7 +108,12 @@ class Tree{
 		}
 	}
 
-	//Deletes the given value
+	/**
+	 * Deletes a given value from the Binary Tree
+	 * 
+	 * @param value Value to be deleted
+	 * @return If the value was deleted
+	 */
 	public boolean remove(int value){
 		//temp is the node to be deleted
 		Node temp = find(value);
@@ -84,34 +137,34 @@ class Tree{
 
 		//Two children
 		else if(temp.left != null && temp.right != null){
-			Node succesor = findSuccesor(temp);
+			Node successor = findSuccessor(temp);
 
 			//The left tree of temp is made the left tree of the successor
-			succesor.left = temp.left;
-			succesor.left.parent = succesor;
+			successor.left = temp.left;
+			successor.left.parent = successor;
 
 			//If the successor has a right child, the child's grandparent is it's new parent
-			if(succesor.right != null && succesor.parent != temp){
-				succesor.right.parent = succesor.parent;
-				succesor.parent.left = succesor.right;
-				succesor.right = temp.right;
-				succesor.right.parent = succesor;
+			if(successor.right != null && successor.parent != temp){
+				successor.right.parent = successor.parent;
+				successor.parent.left = successor.right;
+				successor.right = temp.right;
+				successor.right.parent = successor;
 			}
 			if(temp == root){
-				succesor.parent = null;
-				root = succesor;
+				successor.parent = null;
+				root = successor;
 				return true;
 			}
 
 			//If you're not deleting the root
 			else{
-				succesor.parent = temp.parent;
+				successor.parent = temp.parent;
 
 				//This if/else assigns the new node to be either the left or right child of the parent
 				if(temp.parent.data < temp.data)
-					temp.parent.right = succesor;
+					temp.parent.right = successor;
 				else
-					temp.parent.left = succesor;
+					temp.parent.left = successor;
 				return true;
 			}
 		}
@@ -148,8 +201,14 @@ class Tree{
 		}
 	}
 
-	//Move right once and go left down the tree as far as you can
-	public Node findSuccesor(Node n){
+	/**
+	 * This method finds the Successor to the Node given.
+	 * Move right once and go left down the tree as far as you can
+	 * 
+	 * @param n Node that you want to find the Successor of
+	 * @return The Successor of the node
+	 */
+	public Node findSuccessor(Node n){
 		if(n.right == null)
 			return n;
 		Node current = n.right;
@@ -161,11 +220,20 @@ class Tree{
 		return parent;
 	}
 
+	/**
+	 * Returns the root of the Binary Tree
+	 * 
+	 * @return the root of the Binary Tree
+	 */
 	public Node getRoot(){
 			return root;
 	}
 
-	//Prints leftChild - root - rightChild
+	/**
+	 * Prints leftChild - root - rightChild
+	 * 
+	 * @param localRoot The local root of the binary tree
+	 */
 	public void inOrder(Node localRoot){
 		if(localRoot != null){
 			inOrder(localRoot.left);
@@ -173,7 +241,12 @@ class Tree{
 			inOrder(localRoot.right);
 		}
 	}
-	//Prints root - leftChild - rightChild
+	
+	/**
+	 * Prints root - leftChild - rightChild
+	 * 
+	 * @param localRoot The local root of the binary tree
+	 */
 	public void preOrder(Node localRoot){
 		if(localRoot != null){
 			System.out.print(localRoot.data + " ");
@@ -181,7 +254,12 @@ class Tree{
 			preOrder(localRoot.right);
 		}
 	}
-	//Prints rightChild - leftChild - root
+	
+	/**
+	 * Prints rightChild - leftChild - root
+	 * 
+	 * @param localRoot The local root of the binary tree
+	 */
 	public void postOrder(Node localRoot){
 		if(localRoot != null){
 			postOrder(localRoot.left);

data_structures/DoublyLinkedList.java

@@ -1,19 +1,38 @@
-/*
- * A linked list is similar to an array, it holds values. However, links in a linked list do not have indexes.
- * With a linked list you do not need to predetermine it's size as it grows and shrinks as it is edited.
- * This is an example of a double ended, doubly linked list.
- * Each link references the next link and the previous one.
-*/
-class LinkedList{
-	private Link head; //Head refers to the front of the list
-	private Link tail; //Tail refers to the back of the list
+/**
+ * This class implements a DoublyLinkedList. This is done using the classes
+ * LinkedList and Link.
+ * 
+ * A linked list is simplar to an array, it holds values. However,
+ * links in a linked list do not have indees. With a linked list
+ * you do not need to predetermine it's size as it grows and shrinks
+ * as it is edited. This is an example of a double ended, doubly
+ * linked list. Each link references the next link and the previous
+ * one.
+ * 
+ * @author Unknown
+ *
+ */
 
-	public LinkedList(){
+class DoublyLinkedList{
+	/** Head refers to the front of the list */
+	private Link head;
+	/** Tail refers to the back of the list */
+	private Link tail;
+
+	/**
+	 * Constructor
+	 */
+	public DoublyLinkedList(){
 		head = null;
 		tail = null;
 	}
 
-	public void insertHead(int x){ //Insert an element at the head
+	/**
+	 * Insert an element at the head
+	 * 
+	 * @param x Element to be inserted
+	 */
+	public void insertHead(int x){
 		Link newLink = new Link(x); //Create a new link with a value attached to it
 		if(isEmpty()) //Set the first element added to be the tail
 			tail = newLink;
@@ -23,6 +42,11 @@ class LinkedList{
 		head = newLink; // newLink(head) <--> oldhead
 	}
 
+	/**
+	 * Insert an element at the tail
+	 * 
+	 * @param x Element to be inserted
+	 */
 	public void insertTail(int x){
 		Link newLink = new Link(x);
 		newLink.next = null; // currentTail(tail)     newlink -->
@@ -31,7 +55,12 @@ class LinkedList{
 		tail = newLink; // oldTail <--> newLink(tail) -->
 	}
 
-	public Link deleteHead(){ //Delete the element at the head
+	/**
+	 * Delete the element at the head
+	 * 
+	 * @return The new head
+	 */
+	public Link deleteHead(){
 		Link temp = head;
 		head = head.next; // oldHead <--> 2ndElement(head)
 		head.previous = null; // oldHead --> 2ndElement(head) nothing pointing at old head so will be removed
@@ -40,6 +69,11 @@ class LinkedList{
 		return temp;
 	}
 
+	/**
+	 * Delete the element at the tail
+	 * 
+	 * @return The new tail
+	 */
 	public Link deleteTail(){
 		Link temp = tail;
 		tail = tail.previous; // 2ndLast(tail) <--> oldTail --> null
@@ -47,6 +81,12 @@ class LinkedList{
 		return temp;
 	}
 
+	/**
+	 * Delete the element from somewhere in the list
+	 * 
+	 * @param x element to be deleted
+	 * @return  Link deleted
+	 */
 	public Link delete(int x){
 		Link current = head;
 
@@ -66,6 +106,11 @@ class LinkedList{
 		return current;
 	}
 
+	/**
+	 * Inserts element and reorders
+	 * 
+	 * @param x Element to be added
+	 */
 	public void insertOrdered(int x){
 		Link newLink = new Link(x);
 		Link current = head;
@@ -86,10 +131,18 @@ class LinkedList{
 		}
 	}
 
-	public boolean isEmpty(){ //Returns true if list is empty
+	/**
+	 * Returns true if list is empty
+	 * 
+	 * @return true if list is empty
+	 */
+	public boolean isEmpty(){
 		return(head == null);
 	}
 
+	/**
+	 * Prints contents of the list
+	 */
 	public void display(){ //Prints contents of the list
 		Link current = head;
 		while(current!=null){
@@ -100,24 +153,44 @@ class LinkedList{
 	}
 }
 
+/**
+ * This class is used to implement the nodes of the
+ * linked list.
+ * 
+ * @author Unknown
+ *
+ */
 class Link{
+	/** Value of node */
 	public int value;
-	public Link next; //This points to the link in front of the new link
-	public Link previous; //This points to the link behind the new link
+	/** This points to the link in front of the new link */
+	public Link next;
+	/** This points to the link behind the new link */
+	public Link previous;
 
+	/**
+	 * Constructor
+	 * 
+	 * @param value Value of node
+	 */
 	public Link(int value){
 		this.value = value;
 	}
 
+	/**
+	 * Displays the node
+	 */
 	public void displayLink(){
 		System.out.print(value+" ");
 	}
-}
 
-//Example
-public class DoublyLinkedList{
+	/**
+	 * Main Method
+	 * 
+	 * @param args Command line arguments
+	 */
 	public static void main(String args[]){
-		LinkedList myList = new LinkedList();
+		DoublyLinkedList myList = new DoublyLinkedList();
 
 		myList.insertHead(13);
 		myList.insertHead(7);

data_structures/PriorityQueues.java

@@ -1,21 +1,40 @@
-/*
+/**
+ * This class implements a PriorityQueue.
+ * 
  * A priority queue adds elements into positions based on their priority.
  * So the most important elements are placed at the front/on the top.
  * In this example I give numbers that are bigger, a higher priority.
- * Queues in theory have no fixed size but when using an array implementation it does.
+ * Queues in theory have no fixed size but when using an array
+ * implementation it does.
+ * 
+ * @author Unknown
+ *
  */
 class PriorityQueue{
+	/** The max size of the queue */
 	private int maxSize;
+	/** The array for the queue */
 	private int[] queueArray;
+	/** How many items are in the queue */
 	private int nItems;
 
-	public PriorityQueue(int size){ //Constructor
+	/**
+	 * Constructor
+	 * 
+	 * @param size Size of the queue
+	 */
+	public PriorityQueue(int size){
 		maxSize = size;
 		queueArray = new int[size];
 		nItems = 0;
 	}
 
-	public void insert(int value){ //Inserts an element in it's appropriate place
+	/**
+	 * Inserts an element in it's appropriate place
+	 * 
+	 * @param value Value to be inserted
+	 */
+	public void insert(int value){
 		if(nItems == 0){
 			queueArray[0] = value;
 		}
@@ -30,28 +49,64 @@ class PriorityQueue{
 		nItems++;
 	}
 
-	public int remove(){ //Remove the element from the front of the queue
+	/**
+	 * Remove the element from the front of the queue
+	 * 
+	 * @return The element removed
+	 */
+	public int remove(){
 		return queueArray[--nItems];
 	}
 
-	public int peek(){ //Checks what's at the front of the queue
+	/**
+	 * Checks what's at the front of the queue
+	 * 
+	 * @return element at the front of the queue
+	 */
+	public int peek(){
 		return queueArray[nItems-1];
 	}
 
-	public boolean isEmpty(){ //Returns true is the queue is empty
+	/**
+	 * Returns true if the queue is empty
+	 * 
+	 * @return true if the queue is empty
+	 */
+	public boolean isEmpty(){
 		return(nItems == 0);
 	}
 
-	public boolean isFull(){ //Returns true is the queue is full
+	/**
+	 * Returns true if the queue is full
+	 * 
+	 * @return true if the queue is full
+	 */
+	public boolean isFull(){
 		return(nItems == maxSize);
 	}
 
-	public int getSize(){ //Returns the number of elements in the queue
+	/**
+	 * Returns the number of elements in the queue
+	 * 
+	 * @return number of elements in the queue
+	 */
+	public int getSize(){
 		return nItems;
 	}
 }
-//Example
+
+/**
+ * This class implements the PriorityQueue class above.
+ * 
+ * @author Unknown
+ *
+ */
 public class PriorityQueues{
+	/**
+	 * Main method
+	 * 
+	 * @param args Command Line Arguments
+	 */
 	public static void main(String args[]){
 		PriorityQueue myQueue = new PriorityQueue(4);
 		myQueue.insert(10);

data_structures/Queues.java

@@ -1,16 +1,31 @@
-/*
+/**
+ * This implements Queues by using the class Queue.
+ * 
  * A queue data structure functions the same as a real world queue.
  * The elements that are added first are the first to be removed.
- * New elements are added to the back/rear of the queue. 
+ * New elements are added to the back/rear of the queue.
+ * 
+ * @author Unknown
+ *
  */
 class Queue{
+	/** Max size of the queue */
 	private int maxSize;
+	/** The array representing the queue */
 	private int[] queueArray;
+	/** Front of the queue */
 	private int front;
+	/** Rear of the queue */
 	private int rear;
+	/** How many items are in the queue */
 	private int nItems;
 	
-	public Queue(int size){ //Constructor
+	/**
+	 * Constructor
+	 * 
+	 * @param size Size of the new queue
+	 */
+	public Queue(int size){
 		maxSize = size;
 		queueArray = new int[size];
 		front = 0;
@@ -18,7 +33,13 @@ class Queue{
 		nItems = 0;
 	}
 	
-	public boolean insert(int x){ //Inserts an element at the rear of the queue
+	/**
+	 * Inserts an element at the rear of the queue
+	 * 
+	 * @param x element to be added
+	 * @return True if the element was added successfully
+	 */
+	public boolean insert(int x){
 		if(isFull())
 			return false;
 		if(rear == maxSize-1) //If the back of the queue is the end of the array wrap around to the front
@@ -29,6 +50,11 @@ class Queue{
 		return true;
 	}
 	
+	/**
+	 * Remove an element from the front of the queue
+	 * 
+	 * @return the new front of the queue
+	 */
 	public int remove(){ //Remove an element from the front of the queue
 		if(isEmpty()){
 			System.out.println("Queue is empty");
@@ -42,28 +68,64 @@ class Queue{
 		return temp;
 	}
 	
-	public int peekFront(){ //Checks what's at the front of the queue
+	/**
+	 * Checks what's at the front of the queue
+	 * 
+	 * @return element at the front of the queue
+	 */
+	public int peekFront(){
 		return queueArray[front];
 	}
 	
-	public int peekRear(){ //Checks what's at the rear of the queue
+	/**
+	 * Checks what's at the rear of the queue
+	 * 
+	 * @return element at the rear of the queue
+	 */
+	public int peekRear(){
 		return queueArray[rear];
 	}
 	
-	public boolean isEmpty(){ //Returns true is the queue is empty
+	/**
+	 * Returns true if the queue is empty
+	 * 
+	 * @return true if the queue is empty
+	 */
+	public boolean isEmpty(){
 		return(nItems == 0);
 	}
 	
-	public boolean isFull(){ //Returns true is the queue is full
+	/**
+	 * Returns true if the queue is full
+	 * 
+	 * @return true if the queue is full
+	 */
+	public boolean isFull(){
 		return(nItems == maxSize);
 	}
 	
-	public int getSize(){ //Returns the number of elements in the queue
+	/**
+	 * Returns the number of elements in the queue
+	 * 
+	 * @return number of elements in the queue
+	 */
+	public int getSize(){
 		return nItems;
 	}
 }
-//Example
+
+/**
+ * This class is the example for the Queue class
+ * 
+ * @author Unknown
+ *
+ */
 public class Queues{
+	/**
+	 * Main method
+	 * 
+	 * @param args Command line arguments
+	 */
 	public static void main(String args[]){
 		Queue myQueue = new Queue(4);
 		myQueue.insert(10);

data_structures/SinglyLinkedList.java

@@ -1,58 +1,78 @@
-/*
- * A linked list is similar to an array, it holds values. However, links in a linked list do not have indexes.
- * With a linked list you do not need to predetermine it's size as it grows and shrinks as it is edited.
- * This is an example of a singly linked list. Elements can only be added/removed at the head/front of the list.
-*/
-class LinkedList{
-	private Link head; //Head refers to the front of the list
+/**
+ * This class implements a SinglyLinked List. This is done
+ * using SinglyLinkedList class and a LinkForLinkedList Class.
+ * 
+ * A linked list is implar to an array, it hold values.
+ * However, links in a linked list do not have indexes. With
+ * a linked list you do not need to predetermine it's size as
+ * it gorws and shrinks as it is edited. This is an example of
+ * a singly linked list. Elements can only be added/removed
+ * at the head/front of the list.
+ * 
+ * @author Unknown
+ *
+ */
+class SinglyLinkedList{
+	/**Head refered to the front of the list */
+	private LinkForLinkedList head;
 
-	public LinkedList(){
+	/**
+	 * Constructor of SinglyLinkedList
+	 */
+	public SinglyLinkedList(){
 		head = null;
 	}
 
-	public void insertHead(int x){	//Insert an element at the head
-		Link newLink = new Link(x); //Create a new link with a value attached to it
+	/**
+	 * This method inserts an element at the head
+	 * 
+	 * @param x Element to be added
+	 */
+	public void insertHead(int x){
+		LinkForLinkedList newLink = new LinkForLinkedList(x); //Create a new link with a value attached to it
 		newLink.next = head; 		//Set the new link to point to the current head
 		head = newLink; 			//Now set the new link to be the head
 	}
 
-	public Link deleteHead(){ //Delete the element at the head
-		Link temp = head;
+	/**
+	 * This method deletes an element at the head
+	 * 
+	 * @return The element deleted
+	 */
+	public LinkForLinkedList deleteHead(){
+		LinkForLinkedList temp = head;
 		head = head.next; //Make the second element in the list the new head, the Java garbage collector will later remove the old head
 		return temp;
 	}
 
-	public boolean isEmpty(){ //Returns true if list is empty
+	/**
+	 * Checks if the list is empty
+	 * 
+	 * @return true is list is empty
+	 */
+	public boolean isEmpty(){
 		return(head == null);
 	}
 
-	public void display(){ //Prints contents of the list
-		Link current = head;
+	/**
+	 * Prints contents of the list
+	 */
+	public void display(){
+		LinkForLinkedList current = head;
 		while(current!=null){
 			current.displayLink();
 			current = current.next;
 		}
 		System.out.println();
 	}
-}
-
-class Link{
-	public int value;
-	public Link next; //This is what the link will point to
-
-	public Link(int valuein){
-		value = valuein;
-	}
-
-	public void displayLink(){
-		System.out.print(value+" ");
-	}
-}
-
-//Example
-public class SinglyLinkedList{
+	
+	/**
+	 * Main method
+	 * 
+	 * @param args Command line arguments
+	 */
 	public static void main(String args[]){
-		LinkedList myList = new LinkedList();
+		SinglyLinkedList myList = new SinglyLinkedList();
 
 		System.out.println(myList.isEmpty()); //Will print true
 
@@ -66,4 +86,36 @@ public class SinglyLinkedList{
 
 		myList.display(); // 7(head) --> 5
 	}
+}
+
+/**
+ * This class is the nodes of the SinglyLinked List.
+ * They consist of a vlue and a pointer to the node
+ * after them.
+ * 
+ * @author Unknown
+ *
+ */
+class LinkForLinkedList{
+	/** The value of the node */
+	public int value;
+	/** Point to the next node */
+	public LinkForLinkedList next; //This is what the link will point to
+
+	/**
+	 * Constructor
+	 * 
+	 * @param valuein Value to be put in the node
+	 */
+	public LinkForLinkedList(int valuein){
+		value = valuein;
+	}
+
+	/**
+	 * Prints out the value of the node
+	 */
+	public void displayLink(){
+		System.out.print(value+" ");
+	}
+
 }

data_structures/Stacks.java

@@ -1,62 +1,131 @@
-/*
- *A stack is exactly what it sounds like. An element gets added to top of the stack and only the element on the top may be removed.
- *This is an example of an array implementation of a Stack. So an element can only be added/removed from the end of the array.
- *In theory stacks have no fixed size, but with an array implementation it does.
-*/
+import java.util.ArrayList;
+
+/**
+ * This class implements a Stack using two different implementations.
+ * Stack is used with a regular array and Stack2 uses an ArrayList.
+ * 
+ * A stack is exactly what it sounds like. An element gets added to the top of
+ * the stack and only the element on the top may be removed. This is an example
+ * of an array implementation of a Stack. So an element can only be added/removed
+ * from the end of the array. In theory stack have no fixed size, but with an
+ * array implementation it does.
+ * 
+ * @author Unknown
+ *
+ */
 class Stack{
+	/** The max size of the Stack */
 	private int maxSize;
+	/** The array representation of the Stack */
 	private int[] stackArray;
+	/** The top of the stack */
 	private int top;
 
-	public Stack(int size){ //Constructor
+	/**
+	 * Constructor
+	 * 
+	 * @param size Size of the Stack
+	 */
+	public Stack(int size){
 		maxSize = size;
 		stackArray = new int[maxSize];
 		top = -1;
 	}
 
-	public void push(int value){ //Adds an element to the top of the stack
+	/**
+	 * Adds an element to the top of the stack
+	 * 
+	 * @param value The element added
+	 */
+	public void push(int value){
 		top++;
 		stackArray[top] = value;
 	}
 
-	public int pop(){ //Removes the top element of the stack and returns the value you've removed
+	/**
+	 * Removes the top element of the stack and returns the value you've removed
+	 * 
+	 * @return value popped off the Stack
+	 */
+	public int pop(){
 		return stackArray[top--];
 	}
 
-	public int peek(){ //Returns the element at the top of the stack
+	/**
+	 * Returns the element at the top of the stack
+	 * 
+	 * @return element at the top of the stack
+	 */
+	public int peek(){
 		return stackArray[top];
 	}
 
-	public boolean isEmpty(){ //Returns true if the stack is empty
+	/**
+	 * Returns true if the stack is empty
+	 * 
+	 * @return true if the stack is empty
+	 */
+	public boolean isEmpty(){
 		return(top == -1);
 	}
 
-	public boolean isFull(){ //Returns true if the stack is full
+	/**
+	 * Returns true if the stack is full
+	 * 
+	 * @return true if the stack is full
+	 */
+	public boolean isFull(){
 		return(top+1 == maxSize);
 	}
+	
+	/**
+	 * Deletes everything in the Stack
+	 * 
+	 * Doesn't delete elements in the array
+	 * but if you call push method after calling
+	 * makeEmpty it will overwrite previous
+	 * values
+	 */
 	public void makeEmpty(){ //Doesn't delete elements in the array but if you call
 		top = -1;			 //push method after calling makeEmpty it will overwrite previous values
 	}
 }
 
-
-/* This is ArrayList Implementation of stack , Where size is not
- 	a problem we can extend the stack as much as we want*/ 
+/**
+ * This is an ArrayList Implementation of stack, Where size is not
+ * a problem we can extend the stack as much as we want.
+ * 
+ * @author Unknown
+ *
+ */
 class Stack2{
-		
-		
+		/** ArrayList representation of the stack */
 		ArrayList<Integer> stackList;
 		
-		Stack2(){ //constructor
+		/**
+		 * Constructor
+		 */
+		Stack2(){
 			stackList=new ArrayList<>();
 		}
 		
-		
-		void push(int value){ //adds value to the end of list which is the top for stack
+		/**
+		 * Adds value to the end of list which
+		 * is the top for stack
+		 * 
+		 * @param value value to be added
+		 */
+		void push(int value){
 			stackList.add(value);
 		}
 		
-		int pop(){ //pops last element of list which is indeed the top for Stack 
+		/**
+		 * Pops last element of list which is indeed
+		 * the top for Stack
+		 * 
+		 * @return Element popped
+		 */
+		int pop(){
 			
 			if(!isEmpty()){ // checks for an empty Stack
 				
@@ -71,7 +140,12 @@ class Stack2{
 			
 		}
 		
-		boolean isEmpty(){ //checks for empty Stack
+		/**
+		 * Checks for empty Stack
+		 * 
+		 * @return true if stack is empty
+		 */
+		boolean isEmpty(){
 			if(stackList.isEmpty())
 				return true;
 			
@@ -79,13 +153,28 @@ class Stack2{
 			
 		}
 		
-		int peek(){ //top element of stack
+		/**
+		 * Top element of stack
+		 * 
+		 * @return top element of stack
+		 */
+		int peek(){
 			return stackList.get(stackList.size()-1);
 		}
 	}
 
-//Example
+/**
+ * This class implements the Stack and Stack2 created above
+ * 
+ * @author Unknown
+ *
+ */
 public class Stacks{
+	/**
+	 * Main method
+	 * 
+	 * @param args Command line arguments
+	 */
 	public static void main(String args[]){
 			Stack myStack = new Stack(4); //Declare a stack of maximum size 4
  		//Populate the stack

data_structures/heaps/MaxHeap.java

@@ -84,7 +84,13 @@ public class MaxHeap implements Heap {
 
     @Override
     public void deleteElement(int elementIndex) {
-		if (isempty(maxHeap)) throw new EmptyHeapException("Attempt to delete an element from an empty heap");
+		if (maxHeap.isEmpty())
+			try {
+				throw new EmptyHeapException("Attempt to delete an element from an empty heap");
+			} catch (EmptyHeapException e) {
+				// TODO Auto-generated catch block
+				e.printStackTrace();
+			}
         if ((elementIndex > maxHeap.size()) && (elementIndex <= 0)) throw new IndexOutOfBoundsException("Index out of heap range");
         // The last element in heap replaces the one to be deleted
         maxHeap.set(elementIndex - 1, getElement(maxHeap.size()));

data_structures/heaps/MinHeap.java

@@ -87,7 +87,13 @@ public class MinHeap implements Heap {
 
     @Override
     public void deleteElement(int elementIndex) {
-		if (isempty(maxHeap)) throw new EmptyHeapException("Attempt to delete an element from an empty heap");
+		if (minHeap.isEmpty())
+			try {
+				throw new EmptyHeapException("Attempt to delete an element from an empty heap");
+			} catch (EmptyHeapException e) {
+				// TODO Auto-generated catch block
+				e.printStackTrace();
+			}
         if ((elementIndex > minHeap.size()) && (elementIndex <= 0)) throw new IndexOutOfBoundsException("Index out of heap range");
         // The last element in heap replaces the one to be deleted
         minHeap.set(elementIndex - 1, getElement(minHeap.size()));