CodeSignal Technical Assessment Data Structures 2

Question 1

What is a binary heap used for?

Accepted Answer

Efficiently finding the minimum or maximum element and implementing priority queues

Answer

Binary heaps maintain a partial ordering that allows O(1) access to the min or max element and O(log n) insertion.

Question 2

What is the space complexity of a recursive function with depth n?

Accepted Answer

O(n) due to the call stack

Answer

Each recursive call adds a frame to the call stack, so n levels of recursion use O(n) stack space.

Question 3

What is a trie data structure?

Accepted Answer

A tree-like structure for storing strings where each node represents a character

Answer

Tries store strings character by character in a tree structure, enabling efficient prefix-based operations.

Question 4

What is the time complexity of mergesort?

Accepted Answer

O(n log n)

Answer

Mergesort divides the array in half recursively (log n levels) and merges at each level (n work per level).

Question 5

What is dynamic programming?

Accepted Answer

Solving complex problems by breaking them into overlapping subproblems and storing their solutions

Answer

Dynamic programming avoids redundant computation by storing solutions to subproblems for reuse.

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