CoursesDynamic ProgrammingGrid DP
Boss: Maximal Square
The island's final test: the largest all-ones square in a binary matrix. One min-of-three recurrence certifies every square at once — and the boss's traps are trusting only two neighbors and returning the side when the problem demands the area.
Dynamic Programming is part of AlgoFox Pro
You can read the whole course outline here. The exercises are in the app, along with your streak, your mistake review, and the progress that carries across your devices.
Pro starts with a 3 day free trial. The app store decides who is eligible for an introductory offer, and a lapsed subscription does not get another one.
Already subscribed in the app? Sign in with the same account and Pro works here too. Quick Play and Battle are free on the web, and so is the first course in every subject.