Create UnboundedDeque.java

Author: CodeInSuits

UnboundedDeque.java

@@ -0,0 +1,174 @@
+import java.util.LinkedList;
+public class UnboundedDeque implements InstructuresDeque
+{
+  private int size = 0;
+  private Node sentinel;
+  
+  public class Node
+  {
+    private Object element;
+    private Node prev;
+    private Node next;
+    
+    public Node(Object e)
+    {
+      this.element = e;
+      size++;
+      this.prev = this;
+      this.next = this;
+    }
+    /*public String toString()
+    {
+      if(this.element==null)
+      {
+        return "";
+      }
+      else
+      {
+        return " "+this.element;
+      }
+    }*/
+  }
+  
+  public UnboundedDeque()
+  {
+    this.sentinel = new Node(null);  
+  }
+
+  public int size()
+  {
+    return this.size-1;
+  }
+ 
+  public boolean isEmpty()
+  {
+    if(this.size-1==0)
+    {
+      return true;
+    }
+    else
+    {
+      return false;
+    }
+    
+  }
+  
+
+  public void addTop(Object element)
+  {
+    //if(this.sentinel.next!=this.sentinel)
+    //{
+      Node newNode = new Node(element);
+      Node xnd = this.sentinel.next;
+      newNode.prev = this.sentinel;
+      newNode.next = xnd;
+      xnd.prev = newNode;
+      this.sentinel.next = newNode; 
+    //}
+    /*else
+    {
+      Node newNode = new Node(element);
+      this.sentinel.next = newNode;
+      this.sentinel.prev = newNode;
+      newNode.prev = this.sentinel;
+      newNode.next = this.sentinel;
+    }*/
+  }
+  public void addBottom(Object element)
+  {
+    Node newNode = new Node(element);
+    Node xnd = this.sentinel.prev;
+    newNode.prev = xnd;
+    newNode.next = this.sentinel;
+    xnd.next = newNode;
+    this.sentinel.prev = newNode;
+  }
+  /*public String toString()
+  {
+    String output = "";
+    Node current = this.sentinel.next;
+    while(current!=this.sentinel)
+    {
+      output = output + " " + current;
+      current = current.next;
+    }
+    return output;
+  }*/
+  
+  public Object removeTop() throws IllegalStateException
+  {
+    if(this.size==1)
+    {
+      IllegalStateException e = new IllegalStateException();
+      throw e;
+    }
+    else
+    {
+      Node xnd = this.sentinel.next;
+      this.sentinel.next = xnd.next;
+      xnd.next.prev = this.sentinel;
+      this.size--;
+      return xnd.element;
+    }
+  }
+  public Object removeBottom() throws IllegalStateException
+  {
+    if(this.size==1)
+    {
+      IllegalStateException e = new IllegalStateException();
+      throw e;
+    }
+    else
+    {
+      Node xnd = this.sentinel.prev;
+      this.sentinel.prev = xnd.prev;
+      xnd.prev.next = this.sentinel;
+      this.size--;
+      return xnd.element;
+    }
+  }
+  public Object top()
+  {
+    if(this.size>1)
+    {
+      return this.sentinel.next.element;
+    }
+    else
+    {
+      return null;
+    }
+  }
+  public Object bottom()
+  {
+    if(this.size>1)
+    {
+      return this.sentinel.prev.element;
+    }
+    else
+    {
+      return null;
+    }
+  }
+  public static void main(String[] args)
+  {
+    //UnboundedDeque a = new UnboundedDeque();
+    //System.out.println(a.size());
+    //a.addTop("1231");
+    //a.addTop("123123");
+    //a.addBottom("12312asdasdasd");
+    //a.addBottom("121eadasderqfafasf");
+    //a.addTop("asdasscpioiqwe");
+    //System.out.println(a.bottom());
+    //System.out.println(a.top());
+    //System.out.println(a.removeTop());
+    //System.out.println(a.removeBottom());
+    
+    //a.removeBottom();
+    //System.out.println(a);
+    //System.out.println(a.size());
+   
+  }
+  
+  
+
+}