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

O(n)

Answer

O(1)

Answer

O(n log n)

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 root is the largest element

Answer

The tree is always a complete binary tree with sorted levels

Answer

Left child is always smaller than right child

Question 3

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

Accepted Answer

Queue

Answer

Stack

Answer

Priority Queue

Answer

Deque

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

O(n)

Answer

O(log n)

Answer

O(n²)

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

Stores two data values

Answer

Can only be traversed forward

Answer

Is stored in contiguous memory

Question 6

Which operation on a stack is used to view the top element WITHOUT removing it?

Accepted Answer

peek()

Answer

pop()

Answer

push()

Answer

dequeue()

Question 7

What happens when a hash map experiences a collision?

Accepted Answer

Two keys map to the same bucket and must be resolved by chaining or open addressing

Answer

The new key overwrites the existing key

Answer

The hash map automatically resizes

Answer

The insertion is rejected