Count the subsets of a three-element set.
Acceptance criteria
- 1.#out should show eight subsets.
DSA Tutorial · Backtracking
Practice: Backtracking Explained
These 10 tasks go with the Backtracking Explained chapter. 5 of them ask you to build something small from scratch; 5 give you code that is already broken and ask you to work out why. Set aside about 90 minutes for the whole set, though you can do them in any order.
Nothing here is marked by a person. When you press Submit, the editor checks your code against the points listed under each task and tells you straight away what passed and what didn't (you need a free account to submit). If you get stuck, there are hints, and a worked solution once you've had a go. The first 2 tasks are free; the rest are part of the practice plan.
If it's been a while since you read the chapter, here is how it starts: “Backtracking is brute force with an eraser. You try a choice, follow it, and if it leads nowhere you undo it and try the next — which is why the undo step is the part that matters.” .