CodeSignal Technical Assessment Core Data Structures 2

Question 1

What is the worst-case time complexity for searching an element in a balanced Binary Search Tree (BST)?

Accepted Answer

O(log n)

Answer

A balanced BST has height O(log n), so search eliminates half the remaining nodes at each step.

Question 2

In a min-heap, which statement is always true?

Accepted Answer

Every node is smaller than or equal to its children

Answer

The min-heap property requires every parent node to be less than or equal to its children.

Question 3

Which data structure uses FIFO (First-In, First-Out) ordering?

Accepted Answer

Queue

Answer

A queue strictly processes elements in the order they were added, making the first element added the first removed.

Question 4

What is the time complexity of inserting a key-value pair into a hash map with a good hash function (average case)?

Accepted Answer

O(1)

Answer

With a good hash function and low load factor, insertion computes the bucket index in constant time.

Question 5

A doubly linked list differs from a singly linked list because each node in a doubly linked list:

Accepted Answer

Has a pointer to both next and previous nodes

Answer

Doubly linked list nodes carry both a `next` and a `prev` pointer, enabling bidirectional traversal.

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