C++ Linked Stack Implementation

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Questions and Answers

Which of the following is a primary function of the `Stack` class interface?

Dynamically allocate memory for nodes.
Manage the input and output of data to and from a file.
Specify the basic operations for a stack data structure. (correct)
Define a structure for linked list nodes.

The `LinkedStack` destructor is responsible for preventing memory leaks by deallocating all nodes in the stack.

True (A)

In the `LinkedStack::push` method, what is the purpose of the line `Node* n = new Node(x, head);`?

It creates a new node with data x and sets its next pointer to the current head of the list.

The `LinkedStack::pop` method returns the ______ data from the top node after removing the node.

data Signup and view all the answers

Match the following `LinkedStack` methods with their corresponding actions:

push(const T& x) = Adds a new element to the top of the stack. pop() = Removes and returns the top element from the stack. empty() = Checks if the stack is empty. size() = Returns the number of elements in the stack. Signup and view all the answers

What is the role of the `head` pointer in the `LinkedStack` class?

It points to the top-most element of the stack. (D) Signup and view all the answers

The `LinkedStack::empty()` method returns `true` only if the `sz` variable is equal to 0.

True (A) Signup and view all the answers

Why is it essential to check if the stack is empty before calling `head->getData()` in the `LinkedStack::top()` method?

To prevent accessing memory from a null pointer, which would cause a crash. Signup and view all the answers

In the `LinkedStack` class, the variable `sz` keeps track of the number of ______ in the stack.

elements Signup and view all the answers

Match the following code snippets with their actions inside the `LinkedStack::pop()` method:

<code>T tmp = head->getData();</code> = Stores the data of the current head node. <code>Node* cur = head;</code> = Creates a temporary pointer to the head node. <code>head = head->getNext();</code> = Moves the head pointer to the next node in the stack. <code>delete cur;</code> = Deallocates the memory of the previously top node. Signup and view all the answers

What happens if you call the `pop()` method on an empty `LinkedStack`?

It results in undefined behavior or a crash. (A) Signup and view all the answers

The `display()` method of `LinkedStack` prints out the stack elements in LIFO (Last In, First Out) order.

True (A) Signup and view all the answers

Explain the role of the `Node* n = new Node(x, head);` line in the `push` method.

It allocates a new node on the heap containing the data element x, and sets the 'next' pointer of the new node to point to what was previously the 'head' node. Signup and view all the answers

The `LinkedStack` utilizes a linked list data structure, where each element is stored in a ______.

node Signup and view all the answers

Match the following stack operations to their time complexity in a `LinkedStack` implementation:

push() = O(1) pop() = O(1) top() = O(1) empty() = O(1) Signup and view all the answers

What is a potential disadvantage of using a linked list to implement a stack compared to using an array?

Linked lists require extra memory for storing pointers. (C) Signup and view all the answers

The `Stack` class is an example of an abstract data type (ADT).

True (A) Signup and view all the answers

What does the term 'LIFO' stand for, and how does it relate to the `LinkedStack` implementation?

<code>LIFO</code> stands for Last In, First Out. Elements are added and removed from the top, meaning the last element added is the first one removed. Signup and view all the answers

In the `LinkedStack` implementation, the method that increases the `sz` variable is ______.

push Signup and view all the answers

Match the potential outcomes of each operation on a `LinkedStack` with the stack initially empty:

push(5) = Adds the element 5 to the top of stack, sz = 1. pop() = Results in undefined behavior, as 'head' is nullptr. top() = Returns NULL, as 'head' is nullptr. size() = Returns 0. Signup and view all the answers

Flashcards

Stack

A data structure that follows the Last In, First Out (LIFO) principle.

Stack - Push

Adds an element to the top of the stack.