Solving LeetCode's hardest coding problem, 420 Strong Password Checker

We're solving LeetCode's hardest coding problem, question 420, "Strong Password Checker", because I want to show how to turn any hard problem into a series of easier & approachable problems. And why not start with the hardest one there is!

I PROMISE it'll be doable! I want to make programmers at every level more confident in their abilities!

Images: Photo by Sharon McCutcheon on Unsplash

[toluolu]

Thank you very much Sir! This is the best explanation I have seen for this problem.

[RahulKumar-yoxy]

Damn! That' a lot of hard work there! Really appreciate your efforts and thank you so much for bringing this elegant solution.

[williamiiifarquhar]

This video was very helpful for learning the best solution to the problem. Please keep making videos like this!

[nicolabosco]

Thank you Sir for the explanation! Really good analysis and problem break down.

[hp]

would love to see your explanation on more hard problems like this