Data Structure and Algorithm II

Question 1

What are the key steps in problem solving?

Answer 1

Understand the problem.
Break it down.
Make a plan.
Execute the solution.
Look back to refine.

Question 2

What is an algorithm?

Answer 2

A step-by-step set of instructions to solve a problem or perform a task.

Question 3

What is pseudocode?

Answer 3

A high-level, human-readable description of an algorithm.

Question 4

What is Bubble Sort?

Answer 4

A sorting algorithm that repeatedly swaps adjacent items if they’re in the wrong order.

Time Complexity: O(N²).

Question 5

What is Selection Sort?

Answer 5

Finds the smallest item in the unsorted section and swaps it with the first unsorted item.

Time Complexity: O(N²).

Question 6

What is Insertion Sort?

Answer 6

Builds a sorted section by inserting items one at a time.

Time Complexity: O(N²) average, O(N) best case (sorted array).

Question 7

What is Merge Sort?

Answer 7

A divide-and-conquer algorithm that splits, sorts, and merges halves.

Time Complexity: O(N log N).

Question 8

What is a Binary Search Tree (BST)?

Answer 8

A tree where:

Left child < Parent < Right child.

Question 9

What are BST operations?

Answer 9

Insertion: Place value in the correct position.
Search: Traverse left or right to find the value.
Traversal Orders:
In-Order: Left → Root → Right (sorted order).
Pre-Order: Root → Left → Right.
Post-Order: Left → Right → Root.