Joking. Of course this is because I stayed late nights, learned all the cryptography for one project and educated people about it so no one makes mistakes.

Daily (292/373 streak until LC cap)

Amazing problem, it is not hard actually, I would rate as mid. I had this leetcode pattern in my real interview for big tech, therefore highly recommended.

https://leetcode.com/problems/longest-common-suffix-queries/?envType=daily-question&envId=2026-05-30

#daily #hard #pattern #recommend

Daily (293/373 streak until LC cap)

Easy problem, easy day.

https://leetcode.com/problems/minimum-element-after-replacement-with-digit-sum/description/?envType=daily-question&envId=2026-05-30

#daily #easy #nopattern

Daily (294/373 streak until LC cap)

(Still unsolved, this is for tomorrow)
18% of acceptance, Uber asked it, it is segment tree....

If you are asked segment tree during the interview, probably the role is going to be hard and your interviewer is crazy tough on algos.

Will solve tomorrow, but don't waste time, I think it is better to reject company that asks you segment tree

https://leetcode.com/problems/block-placement-queries/description/?envType=daily-question&envId=2026-05-30

#daily #hard #pattern

Sorry I disappeared and didn't post daily for couple of days as I was working till 1-2AM for Snow. Will tell you more soon, but yeah, not that happy about that.

I will post about Segment tree and Fenwick tree + simple problems for them so that you all have the pattern under you hand to recall it quickly before the interview.

Don't think segment trees are complicated - therefore they are not asked during the real interview, they actually ARE asked, on jun/mid position in big tech (I know it was asked in Databricks)

He brought a friend😆😆

Now I need to provide for them apparently. I guess I need to push for promotion..

Daily (295/373 streak until LC cap)

Actually it is easy question, I don't know why it is labeled as medium. Go for it.

https://leetcode.com/problems/destroying-asteroids/description/?envType=daily-question&envId=2026-05-31

#daily #medium #nopattern

Heap.

As first prerequisite to understand the "array-based" representation of the trees -> we can check heap data structure.

Heap is used to efficiently get minimum (minheap) or maximum (maxheap) element.

You can do it just with plain array: insert all new items, and scan array to find the minimum with O(n) but heap allows O(log(n)) for both insert and findmin() operations.

It can be used as priority queue, in python it is implemented via heapq.
One of the applications can be Dijkstra algorithm that is using priority queue under hood.

In the comments we will discuss different implementations and tree representations.

#leetcode #heap #datastructures

Daily (296/373 streak until LC cap)

Easy, greedy problem

https://leetcode.com/problems/minimum-cost-of-buying-candies-with-discount/description/?envType=daily-question&envId=2026-06-01

#daily #easy #nopattern

Guys, it is last month probably +- few days

Completed daily month streak = 50
Everyday check in: 1 * 30
Everyday daily: 10 * 30
Every week contest button: 5 * 10

50 + 30 + 300 + 50 = 430

Segment tree.

Previously we have discussed Heap. Today we are doing Segment Tree. Don't skip, my friend was asked question for Segment Tree during Data Brix interview - so it is asked, rarely but still.

We will consider the simplest segment tree application range sum query over mutated array: https://leetcode.com/problems/range-sum-query-mutable/description/?envType=problem-list-v2&envId=segment-tree

Go to comments for the DS overview

#leetcode #segmenttree #datastructures

Daily (297/373 streak until LC cap)

Initial thought: wtf? Then I only realize the problem: we need to take ONLY SINGLE ride of land and SINGLE ride of water.
(non-brute-force solution exists)

https://leetcode.com/problems/earliest-finish-time-for-land-and-water-rides-i/description/?envType=daily-question&envId=2026-06-02

#daily #easy #nopattern

Expl:
Usually it is 1-3k impressions per day.
And suddenly, it is 80k spike, but clicks num didnt change.

Daily (298/373 streak until LC cap)

Same problem as yesterday, and the same solution, but just mid

https://leetcode.com/problems/earliest-finish-time-for-land-and-water-rides-ii/description/?envType=daily-question&envId=2026-06-03

#daily #medium #nopattern

I will tell you 100% working fix for memory leak. It was proven already in 2 big tech companies.


The fix is called SDP - safe deployment practices, one of the points there is regular deployment which causes nodes simply to restart.

Typically large companies might have “change freeze” during important event for few weeks. It is overall debatable, as there is data that proves it causes more harm than benefit.

But, the change freeze is typically what reveals memory leak as a problem, and generally people just keep restarting nodes or redeploying the same builds to keep everything healthy.