Daily 337th day streak

Finally we have got some easy, but this easy is on the edge with being medium IMO.
However it is good problem - go for it.

https://leetcode.com/problems/rank-transform-of-an-array/description/?envType=daily-question&envId=2026-07-12

#daily #easy #nopattern

Sound on

Literally this meme

Let's be honest, it is not in the future. I have the project in Snowflake, built from scratch 100% using AI. Even PRs are made by ai, literally vibecoded by very strong people from Google and guys like me (not strong at all).

Performance there is no problem, we did it in rust and using low level kernel stuff. Contrary, as my lead told me, without AI we would probably did slower (but aparently much understandable) solution.

====

Do I think robotics is the future? Well drivers will be done probably soon, not fully replaced, but will be the same as in IT, if government does not intervene, as in USA, people told me there are a lot of "autopilot" taxis nowadays. Delivery - still never heard of massive production case, but probably can be automated as well.

We can see that building good "humanoid" is a bit tricky - so probably some complicated physical work should be okay: plumber, electrician, etc.

===

Disclaimer - I'm extremely bad at analyzing this thing beyond what I see around.

Daily 338th day streak

Not that hard question, just analyze what are the possible numbers that you might generate.
It does not use any specific patterns - therefore a bit bullshit problem.

https://leetcode.com/problems/sequential-digits/description/?envType=daily-question&envId=2026-07-13

#daily #medium #nopattern

Daily 339th day streak

Pretty hard at first glance, but by combining 2 well known patterns it is bearable and solvable, not EXTREMELY hard, just hard.

https://leetcode.com/problems/find-the-number-of-subsequences-with-equal-gcd/?envType=daily-question&envId=2026-07-15

#daily #hard #pattern

Daily 340th day streak

Easy problem, probably the problem that has the SHORTEST solution if you expand your intuition.

https://leetcode.com/problems/gcd-of-odd-and-even-sums/description/?envType=daily-question&envId=2026-07-15

#daily #easy #pattern

Sorry I will spoil, but this is the solution. I think among my 740 solved questions - this is the first time I see it xD

Daily 341th day streak

Easy-Mid problem, just do whatever said in description, again by applying Euclidean algo for gcd.

https://leetcode.com/problems/sum-of-gcd-of-formed-pairs/description/?envType=daily-question&envId=2026-07-16

#daily #medium #nopattern

My advice after 40-50 conducted interviews as an interviewer, and 5-6 as an interviewee:

Never ever use microservices for system design interview
You are never (almost) going to talk about splitting responsibility of the solution between the teams (who owns what). Usually for large products there will be horizontals that you team will not be owning(observability, deployments, rollouts, etc).

Semantical separation and SRP from solid is nice to have but you always trade it with inconsistent state as you need to keep db per microservice (in clean microservices ofc). Sometimes if the requirement is consistency - it is not achievable with clean microservices at all.

I am not even talking about things like they are more expensive, harder to maintain, more cpu intensive because of more network hops and serialization, etc

Daily 342th day streak

Pretty hard question, I have never seen any pattern like that and acceptance rate 22% -> skip it for now.
I will do another "punishment" hard from the list rather that wasting time on that one.

https://leetcode.com/problems/sorted-gcd-pair-queries/description/?envType=daily-question&envId=2026-07-17

#daily #hard #nopattern

Fucking windows.

I just wanted to shut down the machine, but the option was: shut down and update or restart and update. Estimated time: 4 mins

Now it is 20 mins, my guy has restarted 4 times. And it says dont turn off pc while updating

Microsoft, maybe you will fucking let me go home?

Daily 343d day streak

Easy one, again gcd. Now I fully remembered the euclidean algo xD. Go for it.

https://leetcode.com/problems/find-greatest-common-divisor-of-array/description/?envType=daily-question&envId=2026-07-18

#daily #easy #pattern

https://andreyka26.com/how-to-block-ping-icmp-requests-using-ufw

Yeeeah, wrote article about that 2 years ago

#network

in short: if something is not ping(able) - it does not mean that destination IP is not reachable for other protocols, as ping uses ICMP (inside internet layer but on top of IP protocol), whereas bunch of other high level protocols (DNS, HTTP, etc) use IP protocol on the Internet Layer of TCP/IP stack.

So you specifically can block ICMP and let IP work as expected.

#network

Daily 344th day streak

Very good problem, but it was very hard to build intuition about. And also hard to debug personally for me. But it is very good, definitely needs to be done, and has many patterns inside.

https://leetcode.com/problems/smallest-subsequence-of-distinct-characters/description/?envType=daily-question&envId=2026-07-19

#daily #medium #pattern

A bit of content for tomorrow. I had to record (and write an article) as it was planned long time ago, and was asked many times before.

Concurrency article will be ready soon as well.

https://live.andreyka26.com/i-solved-750-leetcode-problems-and-here-what-ive-learnt

Daily 345th day streak

Pretty easy, but required some time for me to do in place.

https://leetcode.com/problems/shift-2d-grid/description/?envType=daily-question&envId=2026-07-20

#daily #easy #nopattern