Number of Islands (Medium) - Daily Leetcode 200 - Day 3 - Solve with Sam in Python

_Note 1: At 2:32 I say and use the term 'waterfall' algorithm, but the correct/common naming is 'floodfill' algorithm._

_Note 2: Removing the set() visited and solely using the grid replacing island cells with water in place has a slight speed improvement, so if modifying the original array is allowed this is a good strategy._

00:00 - Intro
02:17 - Discuss approaches
06:47 - Start solve
23:36 - Test on leetcode
29:21 - Discussion / Attempted optimizations

[tinle]

I would suggest you to zoom in more cause I always have to zoom in on your videos. I like how you approach new problems and really like the process. I'm currently having difficulty on the problem strong password check. Can you go over that one in the future?

[ombieautopilot]

I did this one kind of easily, but the performance statistics showed that my solution outperformed only 17% out them of all. Lol :) Instead of a set I used a 2d-array to mark visited cells. And I think the faster approach here would be to modify the original grid.