Free Practice Quiz Question List

9 Sorting Algorithms Online Quiz Questions

Use this free practice quiz with 20 questions to review 9 Sorting Algorithms, test your knowledge, and prepare for your next test or exam.

20 questions

True or false

1 point

True or false: A stable sorting algorithm preserves the original relative order of records that have equal keys.

A
True
B
False

Choose one

1 point

In bubble sort, what is guaranteed after one complete pass through the current unsorted portion?

A
The smallest unsorted element
B
The largest unsorted element
C
The middle unsorted element
D
The first element examined

Written response

1 point

Which named sorting algorithm is characterized by approximately $n$ swaps while still performing about $n^2$ comparisons?

Fill in the blank

1 point

Insertion sort builds a one element at a time.

Choose one

1 point

What is the best-case time complexity of the standard selection-sort implementation described in the material?

A
$O(n)$
B
$O(n \log n)$
C
$O(n^2)$
D
$O(\log n)$

True or false

1 point

True or false: Merge sort can be stable when its merge operation chooses the left element first whenever two next elements are equal.

A
True
B
False

Choose all

1 point

Which algorithms below are described as stable under the implementations specified in the material? Select all that apply.

A
Bubble sort
B
Insertion sort
C
Merge sort
D
Selection sort

Written response

1 point

How many inversions are in the array $[3, 1, 2]$ ?

Fill in the blank

1 point

In quicksort, the chosen value used to divide the array into partitions is called the .

Choose one

1 point

A small array is already nearly sorted and has few inversions. Which algorithm is the most suitable choice according to the material?

A
Selection sort
B
Insertion sort
C
Merge sort
D
Quicksort with an unrandomized first-element pivot

Choose all

1 point

Which statements about quicksort are supported by the material? Select all that apply.

A
Its average-case time can be $O(n \log n)$ with suitable pivot selection.
B
Its worst-case time is always $O(n \log n)$ .
C
Repeatedly unbalanced partitions can cause $O(n^2)$ time.
D
Its standard implementations preserve equal-key order.

Choose one

1 point

What extra space is required by the usual array implementation of merge sort?

A
$O(1)$
B
$O(\log n)$
C
$O(n)$
D
$O(n^2)$

Open ended

1 point

Recommend suitable algorithms for each of these situations and justify each recommendation: (1) a small, nearly sorted array; (2) records that must retain equal-key order with a guaranteed $O(n \log n)$ time bound; and (3) a setting that prioritizes average-case speed and low extra array memory but can use pivot randomization.

Choose one

1 point

Which algorithm is generally described as using $O(1)$ extra array space for in-place partitioning, while still requiring recursion-stack space?

A
Quicksort
B
Merge sort
C
Selection sort
D
Bubble sort

Choose one

1 point

What is the primary purpose of sorting a collection of items?

A
Rearranging items into a specified order
B
Encrypting every item in an array
C
Removing all duplicate items
D
Randomly changing the positions of items

Choose one

1 point

Why might selection sort be chosen when writing to memory is especially expensive?

A
It guarantees linear running time on every input.
B
It minimizes the number of swaps compared with the other elementary quadratic sorts.
C
It is stable in its standard implementation.
D
It requires $O(n)$ additional array space.

Choose one

1 point

Which situation is the best fit for insertion sort?

A
A large unsorted array where guaranteed $O(n \log n)$ time is required
B
A small array that is already nearly sorted
C
An application that requires the fewest possible comparisons
D
An application that requires stable sorting with $O(n)$ auxiliary memory

True or false

1 point

True or false: The standard implementation of selection sort is stable.

A
True
B
False

Written response

1 point

Using the standard selection sort pseudocode, how many element comparisons are performed when sorting an array of 6 elements?

Written response

1 point

What is the algorithm term for a pair of elements that appears in the opposite order from the desired ordering?