In a multi-stack implementation using a single array, what technique is commonly used to indicate the boundaries between individual stacks?
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.
Storing special delimiter characters within the array.
Using pointers or indices to mark the top and/or bottom of each stack.
Tarjan's algorithm, which leverages a stack, is a prominent algorithm in graph theory. What problem does Tarjan's algorithm solve efficiently?
Determining the minimum spanning tree of a weighted graph.
Finding the shortest path between any two nodes in a graph.
Checking if a given graph is bipartite (can be colored using two colors).
Identifying strongly connected components in a directed graph.
What is the fundamental idea behind memory optimization in stack implementations that use linked lists?
Using a tail pointer in addition to the head pointer to facilitate faster memory deallocation during pop operations.
Storing only the difference between consecutive values in the stack, reducing the memory required per node.
Pre-allocating a large block of memory for stack nodes to reduce the overhead of individual allocations.
Relying on the operating system's virtual memory management to handle memory allocation and deallocation efficiently.
Which of these scenarios would particularly benefit from using a persistent stack?
Implementing undo/redo functionality in a text editor.
Managing function call stacks in a recursive algorithm.
Storing a dynamically changing list of tasks in a to-do app.
Representing the order of web pages visited in a browser's history.
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)
O(1)
O(n^2)
O(n log n)
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.
A new stack is created with the new element, preserving the original stack.
The new element replaces the top element of the original stack.
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?
Popping an element when the stack pointer is at the end of the array.
Pushing an element when the stack pointer is at the end of the array, even if some initial array slots are empty.
Pushing an element when the stack pointer is at the middle of the array.
Popping an element when the stack pointer is at the beginning of the array.
What is the primary challenge in implementing multiple stacks within a single array?
Ensuring data integrity and preventing data corruption between stacks.
Optimizing the search operation across all stacks stored in the array.
Managing the dynamic resizing of the array as stacks grow and shrink.
Maintaining the order of elements within each individual stack.
How can you implement a deque using two stacks effectively?
Use one stack for the front half of the deque and the other for the rear half.
Alternate between pushing elements onto the two stacks, maintaining a balance.
Use one stack for enqueuing and the other for dequeuing, transferring elements when one stack is empty.
Store the deque elements in both stacks simultaneously for redundancy.
Consider a scenario where you need to implement a backtracking algorithm. Which stack implementation would be most suitable?
Multi-stack implementation in a single array
Persistent stack
Double-ended stack (deque)
Standard stack