Hints and the Approach tab

Two different kinds of help, and they are meant to be reached in this order: a hint when you are stuck, the approach when you want to see how it is meant to be done.

Hints#

At the foot of the Description tab is a hint ladder. A problem carries up to five.

They open one at a time - the button offers the next unopened one, not all of them at once. That is the whole point of a ladder: you stop at the one that unsticks you rather than reading five and being handed the answer. Nothing enforces it, though. A hint is not a secret.

We record how many you opened. Since the Practice Score, that count sets the problem's points when you first solve it: one hint makes it worth 75% of its points, two or more 50%. The price is shown before you click ("Revealing this hint makes it worth 2.6 points"), and solving it again later in Revisit restores the full points. The count itself is never shown to anybody else.

A problem with more than five hints does not exist. Past that it stops being a nudge and becomes a walkthrough, which is the next tab's job.

The Approach tab#

The author's explanation of how the problem is meant to be solved: the intuition, usually a brute force worth understanding before discarding, and the approach they were aiming at.

It carries who last updated it and when. A walkthrough written against a signature that has since changed is worse than no walkthrough, so the date is on screen rather than buried.

The target complexity#

Above the walkthrough - and shown even when no walkthrough has been written - is the complexity the author declared for the problem:

Aim for O(n) time, O(n) space.

This is the most useful thing on the tab if you are stuck on how to improve a working solution, because it tells you what you should be reaching for before you read a word of anybody's method.

Related#