Codeforces stream #2 - div1 A-B solving with explanation

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  • Опубліковано 21 лис 2024

КОМЕНТАРІ • 43

  • @filipposoldati1472
    @filipposoldati1472 6 років тому +34

    2:29 Codeforces Round #517 - A: Cram Time
    29:48 Codeforces Round #517 - B: Minimum path
    1:30:30 Codeforces Round #124 - B: Infinite Maze
    2:25:33 Technocup 2019 - Elimination Round 1 - E: Vasya and Good Sequences
    3:31:56 Codeforces Round #272 (Div. 2) - D: Dreamoon and Sets
    Extra:
    3:07:34 Improving suboptimal solution for 517B: Infinite Maze
    3:26:47 Explanation for Educational Codeforces Round 3 - E: Minimum spanning tree for each edge

    • @Errichto
      @Errichto  6 років тому +11

      Thank you a lot!

  • @shrad6611
    @shrad6611 5 років тому +8

    Please, guys, don't always compare him with tourist. He is best in his own way. Here he makes tutorial videos that help many people around the world. According to me he is best and I don't care about, he wins the competition or not but he is only one who helps us, tourist not.

  • @saikat93ify
    @saikat93ify 6 років тому +23

    Appreciate your effort in making this video :)

    • @Errichto
      @Errichto  6 років тому +9

      Cool, I'm glad you liked it :)

  • @rajavikramaditya6152
    @rajavikramaditya6152 6 років тому +4

    I always thot D.E and F were very tough, but you actually made me believe that they are not. Thank you.

  • @arjuntomar215
    @arjuntomar215 6 років тому +2

    great gesture of helping others, it helps a lot please continue these streaming as much as possible ,like me lots of people will love to see your streams very very useful

  • @PedroVillarreal-o6v
    @PedroVillarreal-o6v Рік тому +1

    you are a genius! I wonder how that feels. Although I know not a stitch of what you do, I find it very interesting.

  • @sanjaysingh5007
    @sanjaysingh5007 6 років тому +2

    sir please make more videos on this Type of contest problems of codeforces they teach us alot..your efforts are awesome ...and are helping the students very much...

  • @sanjaysingh5007
    @sanjaysingh5007 6 років тому +2

    sir please make more videos on the algorithms TOPICS and concepts and please tell us about the books our resources to boost our CP skills. Your
    videos are Great...

  • @SuperSam4y0u
    @SuperSam4y0u 5 років тому +1

    Thankyou so much Erichto! Your explanations were really helpful. I hope you keep making such videos and your channel keeps growing!

  • @guttsman
    @guttsman 5 років тому

    This is helping me a lot because this kind of problem almost always have simple and/or smart tricks involved. Thanks for the time invested and hardwork! =D

  • @shrad6611
    @shrad6611 5 років тому

    Make more videos like this which have more explaination
    Love to watch your videos Big fan errichto

  • @dopamineaddict9690
    @dopamineaddict9690 6 років тому

    thanks a lot. the video is great and very educational. please keep making as many of these as possible.

  • @vicfred2989
    @vicfred2989 6 років тому +1

    thanks for making this kind of videos, very appreciated

  • @akhilbinani6246
    @akhilbinani6246 5 років тому

    Codeforces Round #517 - B: Minimum path
    in the first part of the problem instead of DP, we can use Dijkstra`s algorithm to get the same matrix as of the DP matrix.

  • @magnuswootton6181
    @magnuswootton6181 Рік тому +1

    YOU GET TO READ MORE NOTES IF THE NOTES TAKE LESS TIME TO READ. but u read the same amount of words...

  • @mizanurmazumder114
    @mizanurmazumder114 Рік тому

    Wow..! Its really a informative video

  • @ankurdubey960
    @ankurdubey960 6 років тому

    It's really helpful for me. Though best results at 1.25x.

  • @tylerf1902
    @tylerf1902 Рік тому

    very intersting stuff

  • @igorbeliyaveski7600
    @igorbeliyaveski7600 Рік тому

    WOW! Its cool maaaan

  • @siddharthabiswas2147
    @siddharthabiswas2147 5 років тому

    the videos are really good ,thank you

  • @spamfriendly6489
    @spamfriendly6489 Рік тому

    You are a god !

  • @amhanafy
    @amhanafy 6 років тому +1

    why at 16:00 at least one set has (k*(k+1))/4 ??
    and what is k ? the number of remaining numbers from right?

    • @kamildebowski7003
      @kamildebowski7003 6 років тому +2

      If you want to split A numbers into two groups, one group must have at least A/2 numbers. Here we have A=k*(k+1)/2.
      k is the number of remaining numbers on the left.

    • @amhanafy
      @amhanafy 6 років тому

      ok now i know that if we want the remaining space between 2 sets k*(k+1)/4 but how we make sure that there's a space left
      so using the first while loop we make sure that the highest k here equal to i -1 can be splitted to 2 groups
      am i getting it right ?

    • @kamildebowski7003
      @kamildebowski7003 6 років тому +1

      You're getting it right. And the proof was explained in the video.

    • @amhanafy
      @amhanafy 6 років тому

      @@kamildebowski7003 thanks kamil your work is really appreciated looking forward for new live streams
      greetings from Egypt

  • @ahmedshawky9845
    @ahmedshawky9845 6 років тому

    for the first problem how could we prove that you need to select numbers from right to left instead of left to right?

    • @Errichto
      @Errichto  6 років тому +4

      I proved why taking from right to left worked. I also said some intuition why the opposite doesn't work: when you decide about some first numbers, you are left with big numbers that might not fit in either set/bag.

  • @imadudin1522
    @imadudin1522 6 років тому +2

    is this cutoff ?

    • @Errichto
      @Errichto  6 років тому +2

      UA-cam takes a few hours to process a stream, and then it's available in full length, including chat on the side.

    • @imadudin1522
      @imadudin1522 6 років тому +1

      okay, thank you.
      its full now

  • @akaradet5387
    @akaradet5387 Рік тому +2

    ดี

  • @sandipsuryawanshi4788
    @sandipsuryawanshi4788 Рік тому

    Good

  • @darknessgamerz7505
    @darknessgamerz7505 Рік тому

    nostalgia

  • @devidengo
    @devidengo Рік тому

    Juluuiuuu 8:56 u