What is the primary advantage of using a deque (double-ended stack) over a standard stack?
Lower memory consumption for large data sets.
Faster access to elements in the middle of the stack.
Ability to efficiently add or remove elements from both ends.
Improved search efficiency for sorted data.
What is the fundamental idea behind memory optimization in stack implementations that use linked lists?
Relying on the operating system's virtual memory management to handle memory allocation and deallocation efficiently.
Pre-allocating a large block of memory for stack nodes to reduce the overhead of individual allocations.
Storing only the difference between consecutive values in the stack, reducing the memory required per node.
Using a tail pointer in addition to the head pointer to facilitate faster memory deallocation during pop operations.
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.
A new stack is created with the new element, preserving the original stack.
The new element replaces the top element of the original stack.
An error occurs as persistent stacks are immutable.
What is a potential drawback of implementing multiple stacks in a single array with a fixed size?
Risk of stack overflow if the allocated space is insufficient.
Inability to store certain data types within the stacks.
Slower performance compared to using separate stacks.
Increased complexity in managing stack operations.
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.
Pushing an element when the stack pointer is at the middle of the array.
Popping an element when the stack pointer is at the end of the array.
Popping an element when the stack pointer is at the beginning of the array.
Which of the following scenarios is MOST likely to benefit from using a persistent stack data structure?
All of the above.
Implementing an undo/redo functionality in a text editor.
Managing function call stacks in a recursive algorithm.
Storing a history of user actions for analytics purposes.
What is an advantage of using a persistent stack in a concurrent programming environment?
Simplifies data sharing and communication between threads.
Eliminates the need for locks or synchronization primitives.
Improves performance by allowing parallel access to the stack.
Reduces the risk of race conditions and data inconsistencies.
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
Double-ended stack (deque)
Persistent stack
Standard stack
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(1)
O(n)
O(n log n)
O(n^2)
What is a significant advantage of implementing multiple stacks within a single array compared to using separate arrays for each stack?
Reduced space complexity, especially when stack sizes are unpredictable.
Improved time complexity for push and pop operations.
Simplified implementation due to using a single data structure.
Enhanced security by isolating individual stacks within the array.