Your second code has undefined behaviour, since the arrays are uninitialised (accessing the value of uninitialised variable causes undefined behaviour). In the presence of undefined behaviour, compilers often take liberties such as removing code in ways that are counter-intuitive to programmers - in this case, that can result in eliminating one or more of your nested loops. — Peter just now

A textbook quality header, by the way. Two thumbs up. None of the usual mistakes that mess up new C++ programmers. — user4581301 just now

SWIFT exists for 50 years and Swift for how many? 5? 6? So maybe Swift programmers should look for their own tag instead? — Dmitri T 30 secs ago

This is yet another case of not knowing C++ properly enough to involve yourself in questions on LeetCode. The leetcode site, and other "competitive coding" sites assume you know the language you will be using well enough to not make simple mistakes like this -- those sites ask random puzzle questions geared towards experienced programmers. Knowing to use an integer type that will not overflow is basic C++ knowledge. Using leetcode to learn C++ is a waste of time, as that site (and others) are not there to teach C++. — PaulMcKenzie 39 secs ago

@Sina This is yet another case of not knowing C++ properly enough to involve yourself in questions on LeetCode. The leetcode site, and other "competitive coding" sites assume you know the language you will be using well enough to not make simple mistakes like this -- those sites ask random puzzle questions geared towards experienced programmers. Knowing to use an integer type that will not overflow is basic C++ knowledge. Using leetcode to learn C++ is a waste of time, as that site (and others) are not there to teach C++. — PaulMcKenzie 11 secs ago

This is the code for The pascal triangle problem in leetcode: -- Sites such as leetcode assume you know C++ well enough to never make mistakes such as you're making now. The questions on leetcode are geared towards experienced C++ programmers who just want to solve some random puzzle questions. Leetcode and similar "competitive coding" sites are not there to teach basic C++. — PaulMcKenzie just now

In SO, you won't get answers to such questions. You can check at softwarerecs.stackexchange.com or ask in discussion forumns, chat channels etc. — Nishant 42 secs ago

@john softwarerecs.stackexchange.com — Paul Sanders 10 secs ago

Questions that ask "where do I start?" are typically too broad and are not a good fit for this site. People have their own method for approaching the problem and because of this there cannot be a correct answer. Give a good read over Where to Start and edit your post. — Dharman ♦ 44 secs ago

Please read the Open letter to students with homework problems and How do I ask and answer homework questions?. Just copy/pasting your assignments will not win you any friends. — Quentin 25 secs ago

You might find Testing multithreaded race conditions over on Software Engineering worth reading -- the conversation includes mentions of several relevant (albeit mostly not Python-ecosystem-specific) tools, including Helgrind. — Charles Duffy 20 secs ago

Pseudocode is an artificial and informal language that helps programmers develop algorithms — Aviral Jain 54 secs ago

@Essam There really, truly is no way to answer this other than "it's undefined". There are unfortunately pockets of programmers who believe they have some secret means of comprehending these expressions, but since those pockets are insane and don't know C, it's impossible to for an outsider to construct an answer they'd consider "correct". — Steve Summit 50 secs ago

i know im just trying to build up my skill as i want to be a software engineer when i grow up — pugnacious unrest 36 secs ago

Ah, gotcha - thanks for the note on pronouns. I hate to be fussy, and I am aware that this theme is a great irritation for some - I am just conscious that a significant minority of people in tech assume "all software engineers are obviously male", and I have committed myself to calling it out. — halfer 58 secs ago

I don't think this is a good fit for this site since it's quite broad and there's a lot of unknowns, like what the 350 lines of code look like. For example, does each fn* need to access self? Are they pure functions? Would any of the code be useful beyond initializing the class? Speaking of that, I can also imagine a fifth option: moving the functions into the module namespace. Stack Overflow is meant for specific problems -- things preventing you from accomplishing a goal. For this, which is more about design / best practices, it might be better to ask on Software Engineering. — wjandrea 37 secs ago

Recommendation: Always use the optional braces while learning C++ or any other language that uses them. You can leave them out once you're comfortable enough to not make mistakes like this, but after decades of writing code I stull use them religiously because I'm not the only person working on my code and I can't speak for the comfort level of the programmers working with me. — user4581301 27 secs ago

Welcome to Stack Overflow! How to ask homework question and Open letter to students with homework problems — Barmar 20 secs ago

Please use the software recommendations community softwarerecs.stackexchange.com — Esraa Abdelmaksoud 50 secs ago