He's the best competitive programmer in my opinion. He devotes so much to the community. Thankyou errichto!

@Thy_panda_king

3 жыл бұрын

Totally agree 😁

This is a work of art and beauty! There are people who can do but can't teach. Then there are those who can maybe teach but can't do. Then there are legends, who can do both at a mediocre level. And then God said, "Let Errichto be". 🙌. You make complex stuff seem so mind-blowingly simple! Can't thank you enough!

@Errichto

3 жыл бұрын

I think you're exaggerating but still - thank you!

This is the greatest tutorial I have ever seen, soo detailed and crystal clear!!!!!!

@Errichto

3 жыл бұрын

Thanks :)

The transition from logorithm to constant complexity for each query had put a smile. That was so cool.😎. Excellent explanation. Keep it going.

@Errichto

3 жыл бұрын

I agree that the transition is nice and satisfying.

Finally a video that perfectly explains the core concept. I was able to come up with log n approach before you explained and was so proud of myself. And then you dropped constant time which blew my mind. :D Thanks Errichto!

You are the best competitive programmer. Very thanks. I understood it very clearly. Thanks for spending a lot of time to explain us. Thank you Errichto!

Read about sparse table 2 days back. I checked if you had made any video on it. And here it is. 💯

I was looking for sparse table tutorial. When I saw Errichto's video in the list, I knew I couldn't get any luckier.

Video quality and explanation is soo good. Thank-you!!

Thanks for this amazing course. Your explanation is just in another level.

Clear, concise, and perfect explanation

He is really great and down to earth person....always willing to do something good for community....👍👍👍

Errichto this is so nice and simple explanation I read it in book but did not understand you are really nice at explaining

This is very cool. Eager to learn about the segment tree. I didn't know about this. There surely are good use cases for this algorithm. For sure segment trees, or a similar structure, are used in databases.

c++ also has builtin function __lg for base-2 logs with integers. Nice and clear explanation (as always)!

@Errichto

3 жыл бұрын

Oh, right.

@GGxEpsilon

3 жыл бұрын

I think log2 does the same, doesnt it?

@magnuseifr

3 жыл бұрын

@@GGxEpsilon I think __lg belongs to the gcc compiler and is designed to work on integers (or long longs) specifically. log2 should have the same behaviour, but as Errichto mentions in the video: floating point values are scary to work with.

Best Explanation, you made it so easy to understand. Please keep up the good work 😊

Amazing tutorial!!! Really enjoyed it and learned a lot!

Woah explained so simple, seems like a complex math but it is not once you understand the intent behind thanks a lot for the video

Finally Errichto is back :)

that was indeed a really good explanation to sparse tables. Thank you for this video. :)

I love even more your recent videos

Dzięki za pomoc w przygotowaniu do Olimpiady Informatycznej Juniorów (:

i love learning from Errichto more than my own profs

Thank you! Got mine working now! Awesome tutorial!

today i am practice codeforces Div2 C problem but i am not able to solve efficiently and seen editorial sparse table algorithm is used then learn this from your lecture then simply solve and learn this concept smart way very thankful for you explanation

Keep up these good tutorials. Thanks a lot

Thank,I just needed this perfect and Crystal clear explanation .Orz

I don't understand anything you're saying, but your voice is so soothing like ASMR to me

@vaibhavtiwari6540

2 жыл бұрын

Lmao, simp.

Please do some Videos on Data Structure. Your explanations are simple and precise.

Amazing tutorial, for so long I was not sure how queries take constant time and not logN time. I always thought we need to answer each queries such that we divide range into powers of 2... finally your tutorial solved that for me that we need to take largest power of 2 which fits in given range and check from L and R end point and hence it is O(1). thank you so much for clearing this :) Also this clears why we can't use sparse table for answering range sum queries in O(1) because we are using overlapping ranges, right?

Thanks ☺️ , this lecture was really helpful.

Very nice explanation Errichto

You never dissappoint!

amazing dude, I've been following your videos for a year now and you are always improving the way u teach. thanks !

@Errichto

3 жыл бұрын

Let's hope that I will keep improving then :)

Duma rozpiera, że rodak jest takim mózgiem :)

Amazing stuff, good explanation

Wonderful video. Helped me a lot sir

Thank you, Errichto.

may you get all of what you want in life..i respect you

For computing "k" in the query function we can do k=floor(log2(len)) then we can have 2^k

plz do segment tree.. waiting for a long time..

Erichto you are the best person in the world!

Wow! its so clear even a 5 year old IQ guy lile me understands , Thank you for the wonderful content Ericchto !

Great explanation.

The brain on this man

Please make detailed videos on segment tree and it various applications( like, min , max, updating, sum, frequency of max frequent element in the asked range etc...)

Won’t the time complexity for answering a single query still logN as we are computing log2(len) where len is R - L + 1 which in worst case is of the order (N). So won’t the time complexity be logN per query?

He's sooo clever. Thanks for the video

Very nice explanation

Hey Errichto, one question, what do you use in order to write your notes, i think you use like a tablet or something

Can we use sparse table for sum queries if we use the method where we convert ranges to binary and add it like we do in binary lifting (query time = logN)?

the best youtuber

I agree that using log2(x) is something to be avoided generally, however, if x < 2^31, it is guaranteed that the result of (int)log2(x) will be the same of any the bit tricks, so it might be a good choice if it's faster to code.

Thank you !

Hello guys, I am errichto, is so cool to hear

Is the condition in line 30, correct? It does not reflect m[i + (1

What an explanation! op

How do you find problems on SPOJ? It seems so difficult to find by tags.

Should have checked this out before, not knowing sparse tables cost me yesterday as the seg tree failed in time.

Hi , can I know the name of program used to explain pls?

Many thanks!

Errichto can you please make a video on how to deal with burnouts we face while constant coding?

This reminds of Reversort in Codejam Quali

Awesome!!

Thank you for this great video BTW : Is the __builtin function O(1) or O(log) or what ??

@hitesh6856

3 жыл бұрын

It is O(number of bits), so it is essentially O(1)

@Errichto

3 жыл бұрын

@@hitesh6856 It's O(1) rather than O(number of bits). CPU doesn't need to iterate bits one by one, it does it faster just like other basic operations like addition.

@hitesh6856

3 жыл бұрын

​@@Errichto ohh. I didn't knew that. Thanks! big fan..!

@jakoolaboo

3 жыл бұрын

@@Errichto thx for answering

Nice!! Binary is always Beautiful :)

Errichto orz ❤️

It would be nice if you covered CSES problemset. It has a lot of educational problems that are hard to solve if you don't know the right technique.

@KuaisArts

3 жыл бұрын

check out CPH. CSES is a supplementary problem set to that book. Good luck!

Thank you

Can you have multiple overlapping intervals?

legend.

Amazing👍🏽👍🏽

why it is k

@xiangli9588

2 жыл бұрын

you are wrong

❤

You're amazing

I don't know why people disliked this video.🤷‍♂️🤷‍♂️

Thanks You

please do segment trees next

Thanks for this vid - i like your background - so the goal to the get the O(N*log((N) + Q) though N is increasing tremendously ?

@Errichto

3 жыл бұрын

It's O(N*log(N) + Q) so it makes a lot of sense if Q is huge.

Can someone explain me what is “1

@leviackerman9882

3 жыл бұрын

Search bitwise left shift and right shift on KZread Also i think errichto has a video on bit manipulation where he explained left shift and right shift

@leviackerman9882

3 жыл бұрын

Here you go : kzread.info/dash/bejne/qox_rpuScrrNc7w.html

@QngTu1159

3 жыл бұрын

@@leviackerman9882 Tks u so much

@apoorvmehra121

3 жыл бұрын

It means 2 to the power k

pls do video on disjoint set union

I got WA with this code on spoj, do you guys have any ideas?

Line 27, shouldn't it be i

2 year's in and still waiting for the segment tree video

We can also solve this problem using sliding window concept in O(n) time

awesome

💯💯💯

good !

your balance bracket concept apply div2 B problem in contest get Accepted and my rank under 2500 thanks for you good job

@Errichto

3 жыл бұрын

:)

@puneetgoel7416

3 жыл бұрын

What balance bracket concept? Could u pls share the link of that video 🙏🙏

@anshusingh2473

3 жыл бұрын

kzread.info/dash/bejne/op2Il5qdfq-2mMo.html

Segment tree can also do the same right? So whats the advantage here?

@mohansharma-pt6yk

10 ай бұрын

Time complexity becomes O(N+Q*logN) and improves space complexity too

@skt7088

9 ай бұрын

@@mohansharma-pt6yk in segment tree time complexity is O(QlogN)?

How would we handle updates?

@Errichto

3 жыл бұрын

You need a segment tree for that.

Easily explained.

It is like segment tree

i dnno, this guy is godtier. I cannot compute. syntax error

Please do make how and when u started doing cp. Love your videos from Bangladesh

10:00 this was when I started thinking that sparse tables are clever.

I can AC the cses problem but cant for the spoj :))

I saw this somewhere to find largest power of 2 less than or equal to n: x=n While(x&(x-1)) x&=x-1; Now x will be the answer

Hey in preprocessing part inner for loop should be for(i=0;i+(1

I have no idea what queries are, and i am trying to learn