Data Structures Sorting and Searching Algorithms

Question 1

What is the average time complexity of quicksort?

Accepted Answer

O(n log n)

Answer

O(n)

Answer

O(n²)

Answer

O(log n)

Question 2

Which sorting algorithm has the best worst-case time complexity?

Accepted Answer

Merge sort

Answer

Quicksort

Answer

Insertion sort

Answer

Bubble sort

Question 3

What is the key difference between stable and unstable sorting algorithms?

Accepted Answer

Stable sorts preserve the relative order of equal elements; unstable sorts may not

Answer

Stable sorts are always faster

Answer

Stable sorts require O(1) extra space

Answer

Unstable sorts cannot sort strings

Question 4

What is the time complexity of binary search on a sorted array?

Accepted Answer

O(log n)

Answer

O(n)

Answer

O(n log n)

Answer

O(1)

Question 5

Which sorting algorithm is most efficient for nearly sorted data?

Accepted Answer

Insertion sort

Answer

Merge sort

Answer

Heapsort

Answer

Selection sort

Question 6

What is the space complexity of merge sort?

Accepted Answer

O(n)

Answer

O(1)

Answer

O(log n)

Answer

O(n log n)