EnumerativeCombinatorics's blog

YouTube channel: Any requests for algorithm (contest technique) lectures?
By EnumerativeCombinatorics, history, 5 years ago, In English

As I mentioned a few years ago, I make Youtube videos for explaining algorithms and contest techniques (and for me, practicing spoken English). Channel

Recently, after a long break, I restarted making lecture videos on Youtube (I am aiming at posting 1-2 videos per week). I am also posting the upsolving videos of AtCoder Beginner Contests as well. However, I am not sure what algorithms many competitive programmers are curious about.

So this time, I am open for requests: which topic do you want me to explain? Of course, I cannot do everything, there are time constraints and limitations of my ability. However, speaking of algorithms and techniques on programming contests, I have experience and knowledge in each topic as much as I can become a red coder in Codeforces + AtCoder + TopCoder.

Feel free to comment down below. I will try to pick some popular topics from here. (Also I can review onsite contests or reference books or reading weird comments on Codeforces just for fun. I'd appreciate requests for these sections as well :P )

Update: As I have received a lot about dynamic programming (and somehow my DP videos got more attention than others), I'm currently posting Educational DP Contest commentary & implementation one by one as my daily routine. (26 problems in 26 days)

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5 years ago, # |
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A video about Greedy algorithms / DP would be nice! (And your youtube channel is actually not bad, so keep up the good work!)

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5 years ago, # |
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A video about maximum flow and the like.

thanks you for reading

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5 years ago, # |
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Cool. In your ABC upsolving videos, consider opening statements in English if you talk in English anyway. And do cover graphs and strings. People often request it from me and I suck in that, you will do it better.

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5 years ago, # |
  Vote: I like it +9 Vote: I do not like it

A video about bitmask would be nice

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5 years ago, # |
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Please Dont read weird comments on Codeforces it has no benefit to anyone do some hard dp(div2 f / g)

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5 years ago, # |
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Mobius Inversion.

FFT

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    5 years ago, # ^ |
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    I haven't heard such words until red. How about learning how to solve easy problems before learning about FFT?

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      5 years ago, # ^ |
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      I still don’t know both of them, but I peaked LGM lol

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5 years ago, # |
  Vote: I like it +37 Vote: I do not like it

A video about suffix automaton, strings in general.

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5 years ago, # |
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Bridge of tree,Sack,Z Algorithm(Intuition),Arpa's Trick. :)

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5 years ago, # |
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Finally, a decent educational YouTube channel.

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5 years ago, # |
  Vote: I like it +20 Vote: I do not like it

Maybe solving some JOISC problems.

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5 years ago, # |
  Vote: I like it +21 Vote: I do not like it

Please consider making more playlists on specific topics on your channel, it would help viewers to navigate better and you also to keep track on what topic has been covered or if some topic needs improvement.

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    5 years ago, # ^ |
      Vote: I like it +11 Vote: I do not like it

    I am currently making some playlists, but when I have made much more tutorial videos, I would separate them into a few lists, categorized by the algorithms (graph, dp, data structure...).

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5 years ago, # |
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My favourite video is where you speak Tatar language (here), but at 1:18 the word "яратам" is stressed on the last syllable. However, your Tatar is quite nice (especially for a person who doesn't know Russian and doesn't live in Tatarstan)!

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5 years ago, # |
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Some DP type problems and technique like Digit DP, ... and all other useful DP tricks. ^^ . It would be really helpful for people. Thanks in advance for your effort anyway

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5 years ago, # |
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plz solve this problem http://acm.timus.ru/problem.aspx?space=1&num=1745 problem is of timus and problem ID is 1745. This problem involves sorting in a special way. I cant find an article about it and it will be good if you can shed some light on how to tackle problems like this which often involves sorting in special manners. Thankyou!

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5 years ago, # |
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I am personally interested in advanced topics:

I feel these topics require more resources. Different people puts same thing from different perspective and it helps to understand that topic better. So although there are articles in these topics may be 1 or 2, I think more would help.

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5 years ago, # |
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Some trickes related to DP will be great, like digit dp, sum over subsets, expexted value... also I cant see some good video about FFT, am not sure if there is I didnt search lot about it.

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    5 years ago, # ^ |
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    errichto has youtube videoes on expected values.

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5 years ago, # |
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A video about DP-Optimization would be nice. And another one of Advanced DS. Thanks a lot!

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5 years ago, # |
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Please discuss Flow algorithms and questions related to it. There is hardly any video tutorial on it. Thanks!

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5 years ago, # |
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You sound like the nicest person ever. I don't know if it's just a Japanese thing but damn I want to be your friend just like that..

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    5 years ago, # ^ |
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    Japanese are very nice people, but when you get to know them you will find that they are troll masters.

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5 years ago, # |
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Problems from Andrew Stankevich Contests? ... (Since most of them don't have very good editorials and the problems are very good)

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5 years ago, # |
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I would like to find out about the not so "well known" dp tricks and optimizations.

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5 years ago, # |
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About suffix automaton please

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5 years ago, # |
  Vote: I like it +9 Vote: I do not like it

Please do a video on Heavy-Light Decomposition

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5 years ago, # |
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Auto comment: topic has been updated by EnumerativeCombinatorics (previous revision, new revision, compare).

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5 years ago, # |
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There is already a video from Errichto with all problems from educational contest. Maybe you can cover other topics of DP. For example, explain a bit better "a slope trick" link or some other advanced topics.

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5 years ago, # |
  Vote: I like it +13 Vote: I do not like it

Update: As I have received a lot about dynamic programming (and somehow my DP videos got more attention than others), I'm currently posting Educational DP Contest commentary & implementation one by one as my daily routine. (26 problems in 26 days)

Among all the problems and topics, you chose one a few things that already have videos on YT ;p Consider doing CSES dp problems maybe? They are nice and they don't have editorials. https://cses.fi/problemset/

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    5 years ago, # ^ |
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    Wow, didn't know that you did videos on the contest!

    Btw, I'm curious how the problems on the online judge are related to the original book. If the problems are tracing the book, that book should be the best supporting content.

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      5 years ago, # ^ |
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      Nah, I don't think they are that related to each other. Summoning pllk, he will know better.

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        5 years ago, # ^ |
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        Yes, the book and the problem set support each other, but they can also be used independently.

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5 years ago, # |
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I think videos about problems from dunjudge would be good. We cant see other's code their and the problems are nice, without editorials mostly.

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5 years ago, # |
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I heard there are cool local problems in Japan which are not known outside. maybe you can introduce them.

Or you can try marathon broadcast like 300iq, where you solve shitty Japanese problems like Hashigo Sama, Space Pirate. At some point, I tried to solve Space Pirate, but failed because I couldn't even find a solution :D

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5 years ago, # |
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What about problems from Andrew Stankevich Contests ? They are hard , interesting and solution is not on the internet.

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5 years ago, # |
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Hello, I think that it would be very nice to have a video tutorial on the DP optimization known as Alien's trick from IOI 2016 problem Aliens. I haven't found any other resource different than this blog (link to the blog).

Some hard problems that can be solved using this technique are: IOI 2016 — Aliens (link) Balkan OI 2019 — Tennis (link)

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