Hackerrank Python Data Structures & Algorithms 4

Question 1

What does `heapq.heappush(h, item)` guarantee about the resulting list `h`?

Accepted Answer

h[0] is always the smallest element

Answer

h is fully sorted

Answer

h is a max-heap

Answer

h contains no duplicates

Question 2

What is the output of `list(zip([1,2,3], [4,5]))`?

Accepted Answer

[(1,4),(2,5)]

Answer

[(1,4),(2,5),(3,None)]

Answer

[(1,4,2,5)]

Answer

TypeError

Question 3

Which approach correctly implements a graph as an adjacency list in Python?

Accepted Answer

graph = {0: [1,2], 1: [0,2]}

Answer

graph = [[0,1],[1,0]]

Answer

graph = {(0,1), (1,2)}

Answer

graph = [(0,1),(1,2)]

Question 4

What is the average time complexity of `item in my_set` for a Python set?

Accepted Answer

O(1)

Answer

O(n)

Answer

O(log n)

Answer

O(n^2)

Question 5

Which code snippet correctly performs a binary search on a sorted list `arr` for target `t`?

Accepted Answer

import bisect; bisect.bisect_left(arr, t)

Answer

arr.index(t)

Answer

sorted(arr).index(t)

Answer

arr.find(t)

Question 6

What does BFS (Breadth-First Search) use to track nodes to visit next?

Accepted Answer

Queue

Answer

Stack

Answer

Priority queue

Answer

Set

Question 7

What is the time complexity of accessing an element by index in a Python list?

Accepted Answer

O(1)

Answer

O(n)

Answer

O(log n)

Answer

O(n log n)