Heaps & Priority Queues Quiz

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Min-heap vs max-heap, Top K, Kth largest, merging sorted lists and the two-heap median.

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Question 1Select all that apply
What are the costs of a binary heap's operations? (select all that apply)
Peek at min/max: O(1)Push: O(log n)Pop: O(log n)Search for any value: O(1)
Question 2
To find the k-th LARGEST element in O(n log k), you keep…
A min-heap of size kA max-heap of all n elementsA sorted array of size nA queue of size k

Question 3

What does this print?

import heapq
h = [5, 1, 8, 3]
heapq.heapify(h)
print(heapq.heappop(h))

Question 4
How do you get max-heap behaviour with Python's heapq?
heapq.maxheap()Push negated values and negate again when poppingSort in reverse after each pushIt's not possible
Question 5
In Java, how do you create a max-heap of integers?
new PriorityQueue<>()new PriorityQueue<>(Collections.reverseOrder())new MaxHeap<>()new TreeSet<>()
Question 6
Merging k sorted lists with N total nodes using a heap of list heads takes…
O(N·k)O(N log k)O(N log N)O(k)
Question 7
For the running median (Find Median from Data Stream), which structure is standard?
One sorted arrayA max-heap for the smaller half and a min-heap for the larger halfA single min-heapA hash map
Question 8Select all that apply
Which questions are good fits for a heap? (select all that apply)
Top K frequent elementsK closest points to the originCheck if a string is a palindromeReverse a linked list