Data Structures and Algorithms The Complete Masterclass - Min Stacks

The video tutorial discusses the concept of a min stack, a data structure that supports push, pop, top, and retrieving the minimum element in constant time. It explains basic stack operations like push, pop, and top, and introduces the getmin function. The tutorial provides examples and demonstrates how to implement a min stack efficiently by maintaining a separate stack to track minimum values.

What is the primary function of the 'push' operation in a stack?

• To remove the top item from the stack

• To add an item to the stack

• To view the top item of the stack

• To sort the items in the stack

Which operation would you use to view the topmost item of a stack without removing it?

• Pop

• Top/Peek

• Push

• Insert

What does the 'pop' operation do in a stack?

• Removes the top item from the stack

• Returns the minimum item in the stack

• Adds an item to the stack

• Duplicates the top item of the stack

What additional functionality does a min stack provide over a regular stack?

• It allows sorting of elements

• It retrieves the minimum element in constant time

• It provides the maximum element

• It duplicates the stack

How does the 'getMin' operation in a min stack differ from a regular stack?

• It retrieves the last element

• It retrieves the maximum element

• It retrieves the minimum element in constant time

• It retrieves the top element

What is the time complexity goal for retrieving the minimum element in a min stack?

• O(n)

• O(n^2)

• O(log n)

• O(1)

What is the purpose of maintaining a separate min stack?

• To store all elements in sorted order

• To duplicate the main stack

• To keep track of the maximum value

• To keep track of the minimum value at each step

In the context of a min stack, what happens when the minimum element is popped?

• The stack becomes empty

• The maximum element becomes the new minimum

• The next minimum is retrieved from the min stack

• The stack is sorted

What is the main advantage of using a min stack?

• It allows for dynamic resizing

• It increases the stack's capacity

• It provides constant time retrieval of the minimum element

• It automatically sorts the stack

Which data structure can be used to implement a stack?

• Queue

• Array

• Graph

• Tree