Daily 370th day streak

Amazing problem. Definitely recommended. Has pattern.

The solution is just a form of solution from "Daily 368th day".

https://leetcode.com/problems/maximum-length-substring-with-two-occurrences/description/?envType=daily-question&envId=2026-08-14

#daily #easy #pattern

btw, now gestalt is over. I have enough coins for T-shirt (as bunch of my ex-Microsoft coworkers had T-shirts from LC).

Now feel much better😁

We found the root cause. I mean one senior in US (blindly or not) did a fix and it helped. However it shouldn’t.

Then I investigated why it helped? And it took me 4 hours of checking how rust runtime and thread pool works internally, what kernel does with socket.accept(), socket.recv(). What is the difference between blocking recv() and non-blocking .recv() via epoll.wait() (essentially how your async I/O works in high languages)

Do you want to see simple use case with deep dives into kernel and why it happened(probably short video or/and post here)?

Daily 371st day streak

Nice binary/bitwise brain puzzle. The problem is not hard once you realize the XOR, how it works, and if you have seen XOR problems before.

I will just remind that I had 2 interviews (real ones) in bigtech that involved some sort of binary operations and numbers

https://leetcode.com/problems/longest-subsequence-with-non-zero-bitwise-xor/description/?envType=daily-question&envId=2026-08-15

#daily #medium #recommend

Omg. Second time I end up in the AI circle with Opus 5 asking about low level tokio runtime, async there, etc.

This thing annoyed me so much. I already realised the async await on the kernel level with c (how is it in nodejs and .net, and a bit in rust).
But rust still remains with some unknowns that do not connect in my mind. Will try tomorrow.

This is the worst feeling. I woke up with the feeling I understand stuff for 80%, I need to cover remaining 20% of understanding. This tucker left me with 60% now. This specific agent I was talking to whole day - I hope you’ll be shut down😁

Daily 372nd day streak

I do not recommend this one. No pattern, greedy math/scenarios masturbation that just situational for that particular problem. Put a dislike if you can. Hate such problems. No learning, no reusing.

https://leetcode.com/problems/stone-game-ix/description/?envType=daily-question&envId=2026-08-16

#daily #medium #nopattern

Idk, they are so funny to me for some reason😁
Lately was going them snickers, but they were too afraid, so I had to go 10 meters away

Giving an update: leaning kernel non blocking stuff.

Sorry, but ai am really DFS person. Once I start learning I am hooked about something due to curiosity, and here we go - checking kernel c code, reading kernel books etc.

But result worth it guys. You ‘ll get 8 pages article that just gives complete mental model without AI hallucinations + code examples.

someone: ASYNC IS JUST PROMISE!!!!😁😁😁

me: yeeeeeeah, just promise.....

pls, this diagram is not ready, but it covers general idea of it, I will get back to polishing and checking its correctness when claude is back to life

Probably claude learnt too much ukrainian swearing today and now needs to rethink its life😆😆😆

Poor guy suicided after what I said to him with my prompt engineering

Daily 373d day streak

Nice DP problem. Actually it is not that hard at all. Classic dp and that's it + some other pattern (figure it out). I do recommend.

https://leetcode.com/problems/stone-game-v/description/?envType=daily-question&envId=2026-08-17

#daily #hard #pattern

Hopefully somebody is interested.
This is what is going on in the kernel for blocking socket.read() -> blue line

Blocking -> means the thread in usermode that called it goes to sleep up until there is ready response in socket buffer.

Then interrupt (push model) on Network card pushes notification that data has arrived (0). CPU gets the interrupt (same push model) and triggers softirq action that stars executing the interrupt handler kernel code.

Note: `CPU checks for pending interrupts between every instruction and if there is interrupt CPU pushes pointer to interrupt instructions`

It then pushes socket buffer to "receive_queue" - the actual =data (1)

And wakes up (.wakeup()) corresponding entry that points to task(the one that kernel schedules on CPU).

Essentially wakeup() marks task as runnable and puts to run queue, from where it will be scheduled by kernel and that's how your user space process will get the data coming from the socket

#kernel #network

Github enterprise is down. Means - unlimited coffee break

(Personal github still works)

Daily 374th day streak

WTF 35% acceptance rate for easy???
Btw to me problem was not hard, if you just go and do bruteforce. So go for it, it has pattern.

https://leetcode.com/problems/find-the-largest-almost-missing-integer/description/?envType=daily-question&envId=2026-08-18

#daily #easy #pattern

This is how you should use engineering and vibecoding.

Big respect to the guy.

Stop making 101st financial/habbit tracker(said the guy who did 10th symptoms tracker😁)

Legend. After doing low level kernel stuff with rust, ebpf with c, semi custom tls psk with custom pki. I agree with him.

“Just do actual thing, actual programming“😁

https://youtu.be/2jqS7wN-yzs?is=hKYv1LzVn6WwswD0

I am myself web dev to some extent, at least I was, and I dont find it insulting or something for some reason - more like funny. Maybe I like the guy, he has low level c aura.

Dont get me wrong, there is actual complexity in backend and frontend to keep code easy to read and update.

BUT, you all probably saw https://github.com/EnterpriseQualityCoding/FizzBuzzEnterpriseEdition


Which is good example of making flexible and extendable things that do not need it, and putting all tons of SOLID/patterns where they are not needed. It is like applying DDD and clean architecture for btree impl(I was doing that at some point)

Daily 375th day streak

Pretty easy, just you should be careful to not hit Memory Limit Exceeded (check the comments)
No pattern though.

https://leetcode.com/problems/cinema-seat-allocation/description/?envType=daily-question&envId=2026-08-19

#daily #medium #nopattern

We were all talking about the AI costs. Today I realised what is my number😁