Amazon SDE-1 2026 - Coding Basics

Question 1

What is the time complexity of inserting into a hash table (average case)?

Accepted Answer

O(1)

Answer

O(log n)

Answer

O(n)

Answer

O(n log n)

Question 2

Which data structure is used for BFS traversal?

Accepted Answer

Queue

Answer

Stack

Answer

Heap

Answer

Tree

Question 3

What is the worst-case time complexity of QuickSort?

Accepted Answer

O(n²)

Answer

O(n log n)

Answer

O(n)

Answer

O(log n)

Question 4

In a max-heap, where is the maximum element always located?

Accepted Answer

Root

Answer

Leaf

Answer

Middle level

Answer

Random

Question 5

Which search algorithm requires sorted data?

Accepted Answer

Binary Search

Answer

Linear Search

Answer

DFS

Answer

BFS

Question 6

What is the space complexity of merge sort?

Accepted Answer

O(n)

Answer

O(1)

Answer

O(log n)

Answer

O(n²)

Question 7

Which traversal visits left, root, right?

Accepted Answer

Inorder

Answer

Preorder

Answer

Postorder

Answer

Level-order

Question 8

Dynamic programming typically improves recursion by:

Accepted Answer

Memoization

Answer

Parallelizing

Answer

Compilation

Answer

Inlining

Question 9

Which is NOT a stable sorting algorithm?

Accepted Answer

QuickSort

Answer

Merge Sort

Answer

Bubble Sort

Answer

Insertion Sort

Question 10

A linked list of n nodes - what is the time to access the kth element?

Accepted Answer

O(k)

Answer

O(1)

Answer

O(log n)

Answer

O(n)