Stack & Queue Quiz — Quiz

Question 1

A stack follows which order?

Last In, First Out (LIFO)First In, First Out (FIFO)Sorted orderRandom order

Question 2Select all that apply

Which strings are valid bracket sequences? (select all that apply)

()[]{}{[()]}([)]((

Question 3

What does this RPN expression evaluate to: ["2", "1", "+", "3", "*"]?

Question 4

In RPN, for the tokens ["5", "2", "-"], what is the result?

Question 5

How does a Min Stack return the minimum in O(1)?

It sorts after every pushEach entry also stores the minimum at that level of the stackIt scans the stack on every getMinIt uses a queue

Question 6

For "Daily Temperatures" (next warmer day), the monotonic stack keeps temperatures…

Decreasing from bottom to topIncreasing from bottom to topSorted after every pushRandom

Question 7

What is the time complexity of the monotonic stack solution for next greater element?

O(n²)O(n)O(n log n)O(1)

Question 8

Which Python structure should you use as a queue?

list with pop(0)collections.deque with popleft()setdict