Technical Interview Problems: Lists
A collection of common interview problems that use the Python List, and strategies for how to construct optimal solutions.
Start
Technical Interview Problems in Python: Lists
Lesson 1 of 1
- 1Lists are a fundamental data type in Python. Projects make extensive use of lists to store data in sequential order. You should expect at least one technical interview question that requires wo…
- 2For our first problem, we would like to “rotate” a list, or move elements forward in a list by a number of spaces, k. Elements at the greatest index will “wrap around” to the beginning of the …
- 3Optimizing a solution means reducing the memory required (space complexity), or reducing the number of instructions the computer must execute (time complexity). Sometimes this means entirely reth…
- 4We’ll continue our theme of list rotation by flipping the problem: given a sorted list rotated k times, return the index where the “unrotated” list would begin. rotated_list = [‘c’, ‘d’, ‘e’, …
- 5Our last problem had a sorted dataset as the input. Sure, it was rotated, but it started out sorted. A sorted list gives us ways to leverage that ordering. After all, someone went through a lo…
- 6Duplicate values? Who needs them! Given a list of values with duplicates, return a list holding the same values in the same order with all duplicates removed. duplicates = [‘a’, ‘a’, ‘x’, ‘x’…
- 7For the last problem our suggested solutions had O(N) time and/or O(N) space complexity. We can’t improve the time complexity. We have to visit each value to determine whether or not it is a dupli…
- 8Our next problem calculates sums within a list. Given a list of integers, return the maximum sum possible from a contiguous sub-list. A sub-list is an uninterrupted portion of the list (up to…
- 9Our last solution had a cubic time complexity: O(N^3). One iteration for the length of the list O(N), inside another iteration for the length of the list O(N^2), inside the inner loop, we copi…
- 10We’ll end with a classic interview question: given a list of integers and a “target” integer, return a pair of indices whose values sum to the target. nums = [4, 2, 8, 9, 6] target = 8 pair_s…
- 11We’ll explore a common trade-off: time vs. space. Our previous solution used nested for loops to iterate through each element in the list and then iterate again for each element in the list to…
What you'll create
Portfolio projects that showcase your new skills
How you'll master it
Stress-test your knowledge with quizzes that help commit syntax to memory