12.2

public boolean contains (int item)
{ 
   Node current = head;
   boolean found = false; 
   while (!found && current != null)
      if (current.info == item) 
         found = true; 
      else 
         current = current.link;
   return found;
} 

public void deleteAll (int item)
{ 
   // First delete any values at the front of list
   while (head != null && head. info == item) 
      head = head. link; 
   // Now delete any items not at the front of the list
   if (head != null && head.link != null) 
   { 
      Node current = head.link;
      Node previous = head;
      while (current != null) 
         if (current.info == item) 
         { 
            pevious.link = current.link;
            current = current.link;
         } 
         else 
         { 
            previous = current;
            current = current.link;
         }
   }
} 

public boolean isOrderedlncreasing ()
{ 
   boolean result = true;
   if (head != null) 
   { 
      Node previous = head;
      Node current = head.link;
      while (current != null && result)
        if (current.info.compareTo(previous.info) <= 0)
           result = false; 
        else
        { 
           previous = current;
           current = current.link;
        }
   }
} 

public void insert(int item)
{ 
   if (head == null) 
      head = new Node(item,null);
   else if (item < head. info) 
      head = new Node(item,head);
   else
   { 
      // Locate insertion point
      Node current = head;
      boolean located = false; 
      while (!located && current.link != null)
      if (item < current.link.info)
         located = true; 
      else
         current = current.link;
      // Perform insertion 
      if (located) // Normal insertion
      { 
         Node temp = new Node(current.info,current.link);
         current.info = item; 
         current.link = temp; 
      } 
      else // Insert at end of list
         current.link = new Node(item,null); 
   }
} 

public boolean isIdentical (List other)
{ 
   if (other == null)
      return false;
   else if (head == null && other.head == null)
      return true; 
   else if (head == null || other.head == null)
      return false; 
   else 
   {
      Node current = head; 
      Node otherCurrent = other.head;
      while (true) 
      { 
         if (current.info != otherCurrent.info)
            return false; 
         else if (current.link == null && otherCurrent.link == null)
            return true; 
         else if (current.link == null || otherCurrent.link == null)
            return false; 
         else 
         {
            current = current.link;
            otherCurrent = otherCurrent.link; 
         }
      }
   }
}