In a persistent stack implementation, what happens when you push a new element onto the stack?
The original stack is modified to include the new element.
An error occurs as persistent stacks are immutable.
The new element replaces the top element of the original stack.
A new stack is created with the new element, preserving the original stack.
Consider a scenario where you need to implement a backtracking algorithm. Which stack implementation would be most suitable?
Persistent stack
Multi-stack implementation in a single array
Standard stack
Double-ended stack (deque)
In the largest rectangle in a histogram problem, we aim to find the rectangle with the maximum area within a given histogram. How does the stack help in efficiently determining the area of potential rectangles?
The stack stores the heights of the bars in increasing order, allowing for quick area calculation.
The stack keeps track of the starting indices of potential rectangles, enabling efficient width calculation.
The stack maintains the areas of all previously encountered rectangles for comparison.
The stack is not used in the most efficient solutions to this problem.
In a multi-stack implementation using a single array, what technique is commonly used to indicate the boundaries between individual stacks?
Storing special delimiter characters within the array.
Using pointers or indices to mark the top and/or bottom of each stack.
Employing a hash table to map stack identifiers to their corresponding array ranges.
Maintaining separate arrays to track the top and bottom of each stack.
Which data structure is often used in conjunction with a persistent stack to efficiently manage the different versions of the stack?
Hash table
Binary tree
Linked list
Queue
How can you implement a deque using two stacks effectively?
Alternate between pushing elements onto the two stacks, maintaining a balance.
Store the deque elements in both stacks simultaneously for redundancy.
Use one stack for enqueuing and the other for dequeuing, transferring elements when one stack is empty.
Use one stack for the front half of the deque and the other for the rear half.
Which of these scenarios would particularly benefit from using a persistent stack?
Managing function call stacks in a recursive algorithm.
Implementing undo/redo functionality in a text editor.
Representing the order of web pages visited in a browser's history.
Storing a dynamically changing list of tasks in a to-do app.
Tarjan's algorithm, which leverages a stack, is a prominent algorithm in graph theory. What problem does Tarjan's algorithm solve efficiently?
Checking if a given graph is bipartite (can be colored using two colors).
Determining the minimum spanning tree of a weighted graph.
Finding the shortest path between any two nodes in a graph.
Identifying strongly connected components in a directed graph.
The stock span problem requires finding the number of consecutive days before each day with a stock price less than or equal to the current day's price. What is the time complexity of the most efficient algorithm for this problem using a stack?
O(n log n)
O(n)
O(1)
O(n^2)
Imagine you're implementing a stack with a fixed-size array. Which situation leads to a stack overflow even if the number of elements in the stack is less than the array's size?
Pushing an element when the stack pointer is at the end of the array, even if some initial array slots are empty.
Popping an element when the stack pointer is at the beginning of the array.
Popping an element when the stack pointer is at the end of the array.
Pushing an element when the stack pointer is at the middle of the array.