CodeSignal Technical Assessment Data Structures

Question 1

What is the time complexity of accessing an element in an array by index?

Accepted Answer

O(1)

Answer

O(n)

Answer

O(log n)

Answer

O(n²)

Question 2

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

Accepted Answer

Queue

Answer

Stack

Answer

Tree

Answer

Graph

Question 3

What is the time complexity of searching in a balanced binary search tree?

Accepted Answer

O(log n)

Answer

O(1)

Answer

O(n)

Answer

O(n²)

Question 4

What is a hash table collision?

Accepted Answer

When two different keys hash to the same index

Answer

When a hash table is full

Answer

When a key cannot be found

Answer

When the hash function fails

Question 5

What is the difference between a stack and a queue?

Accepted Answer

Stack uses LIFO (last in, first out); queue uses FIFO (first in, first out)

Answer

They are identical

Answer

Stack is faster

Answer

Queue uses more memory

Question 6

What is a linked list advantage over an array?

Accepted Answer

Efficient insertion and deletion without shifting elements

Answer

Faster random access

Answer

Less memory usage

Answer

Built-in sorting