Algorithm facts & stats

Question 1

Binary search only works on a list that is what?

Accepted Answer

Sorted. Binary search halves the search range each step, which requires the items to be in sorted order.

Question 2

What is a recursive function?

Accepted Answer

A function that calls itself. A recursive function solves a problem by calling itself on smaller versions of the same problem.

Question 3

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

Accepted Answer

O(log n). Each step of binary search halves the remaining items, giving logarithmic time.

Question 4

What is the worst-case time complexity of bubble sort?

Accepted Answer

O(n²). Bubble sort may compare and swap neighbors across the list many times, giving quadratic time.

Question 5

What does Dijkstra's algorithm find?

Accepted Answer

Shortest paths in a graph with non-negative edge weights. Dijkstra's algorithm finds the shortest paths from a starting node when edge weights are not negative.

Question 6

What is the worst-case time complexity of merge sort?

Accepted Answer

O(n log n). Merge sort splits the list in half repeatedly and merges in linear time, always giving O(n log n).

Question 7

What is the worst-case time complexity of quicksort?

Accepted Answer

O(n²). Quicksort averages O(n log n), but consistently bad pivot choices degrade it to O(n²).

Algorithm facts & stats

The basics