verse down the tree and one to traverse up the tree. Your implementation should guarantee

Create a singly linked list of nodes and frequently retrieve data from it at random intervals to implement a self-organizing list. Show what happens to the list when the count, move to front, and transpose methods are applied to the same collection of frequently retrieved items.

In Java,  Complete the incomplete method of ExpressionTree.java. The incomplete methods are private Node parsePrefix(Scanner input) // Required public void parseInfix(String string) // Optional public void parsePostfix(String string) // Optional Implementations of parseInfix and parsePostfix require use of a stack. Implementation of parsePrefix does not. Read all of the ExpressionTree.java file before starting your implementation, so that you see the helper methods that are provided and get an idea of the context for your implementation.  Although not needed for your implementation, you should be sure you understand how the toStringPrefix, toStringInfix, and toStringPostfix methods work. Note: The main() method accepts a single String as its argument. The String should be a prefix, infix, or postfix mathematical expression with no characters other than operators (+, -, *, and /) and operands (single characters a-z).  As written, the main() method calls parsePrefix() to create an…

def has_at_least(queue: Queue, n: int) -> bool:"""Return true iff queue contains at least n items. Precondition: n >= 0 >>> queue = Queue()>>> queue.enqueue(1)>>> queue.enqueue(2)>>> queue.enqueue(3)>>> has_at_least(queue, 3)True"""

Implement the following function, in which a while loop is used to keep taking out two minimum elements from the tree, by calling heapq.heappop (), and then merging them to a new node, and lastly inserting the new node back to tree. Note that: • The new node does not need to have a self.char attribute, so you can let it be None Remember to specify the left and right children nodes correctly for the new node. The function changes tree in place. So, you don't need to return tree In [ ]: def merge_nodes (tree): ### START YOUR CODE ### while(len(tree)>1): # Specify the loop condition (you can use while or for) nodel = None node2 = None merged = None # Create a new node by merging the two popped nodes pass # Remember to specify the left and right children nodes for merged pass # Insert the new node to the tree ### END YOUR CODE ### In [ 1: # Do not change the test code here sample_text = 'No, it is a word. What matters is the connection the word implies.' freq =…

Design a more efficient version of HeapVector that keeps its values in order only when necessary: When values are added, they are appended to the end of the existing heap and a nonHeap flag is set to true. When values are removed, the nonHeap flag is checked and the Vector is heapified if necessary. What are the worst-case and best-case running times of the add and remove operations?

A double linked list may be implemented in a workspace array by utilising only one index next. That is, we do not need to retain a distinct field back in the workspace array nodes to detect the backward linkages. The goal is to add a member workspace[current] into workspace[current] rather than the index of the next element on the list. The difference is the index of the next item less the index of the entry preceding current. We must additionally keep two pointers to subsequent nodes in the list, the current index and the prior index of the node right before current in the linked list.To find the next entry of the list, we calculate workspace[current].difference + previous; Similarly, to find the entry preceding previous, we calculate current − workspace[previous].difference;