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

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  • เผยแพร่เมื่อ 3 ธ.ค. 2024

ความคิดเห็น • 43

  • @filipposoldati1472
    @filipposoldati1472 6 ปีที่แล้ว +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 ปีที่แล้ว +11

      Thank you a lot!

  • @shrad6611
    @shrad6611 5 ปีที่แล้ว +9

    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 ปีที่แล้ว +23

    Appreciate your effort in making this video :)

    • @Errichto
      @Errichto  6 ปีที่แล้ว +9

      Cool, I'm glad you liked it :)

  • @arjuntomar215
    @arjuntomar215 6 ปีที่แล้ว +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

  • @rajavikramaditya6152
    @rajavikramaditya6152 6 ปีที่แล้ว +4

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

  • @SuperSam4y0u
    @SuperSam4y0u 6 ปีที่แล้ว +1

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

  • @PedroVillarreal-o6v
    @PedroVillarreal-o6v ปีที่แล้ว +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 ปีที่แล้ว +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...

  • @guttsman
    @guttsman 5 ปีที่แล้ว

    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

  • @sanjaysingh5007
    @sanjaysingh5007 6 ปีที่แล้ว +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...

  • @vicfred2989
    @vicfred2989 6 ปีที่แล้ว +1

    thanks for making this kind of videos, very appreciated

  • @shrad6611
    @shrad6611 5 ปีที่แล้ว

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

  • @dopamineaddict9690
    @dopamineaddict9690 6 ปีที่แล้ว

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

  • @mizanurmazumder114
    @mizanurmazumder114 ปีที่แล้ว

    Wow..! Its really a informative video

  • @amhanafy
    @amhanafy 6 ปีที่แล้ว +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 ปีที่แล้ว +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 ปีที่แล้ว

      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 ปีที่แล้ว +1

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

    • @amhanafy
      @amhanafy 6 ปีที่แล้ว

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

  • @magnuswootton6181
    @magnuswootton6181 ปีที่แล้ว +1

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

  • @siddharthabiswas2147
    @siddharthabiswas2147 5 ปีที่แล้ว

    the videos are really good ,thank you

  • @igorbeliyaveski7600
    @igorbeliyaveski7600 ปีที่แล้ว

    WOW! Its cool maaaan

  • @tylerf1902
    @tylerf1902 ปีที่แล้ว

    very intersting stuff

  • @spamfriendly6489
    @spamfriendly6489 ปีที่แล้ว

    You are a god !

  • @akhilbinani6246
    @akhilbinani6246 5 ปีที่แล้ว

    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.

  • @ankurdubey960
    @ankurdubey960 6 ปีที่แล้ว

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

  • @ahmedshawky9845
    @ahmedshawky9845 6 ปีที่แล้ว

    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 ปีที่แล้ว +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 ปีที่แล้ว +2

    is this cutoff ?

    • @Errichto
      @Errichto  6 ปีที่แล้ว +2

      TH-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 ปีที่แล้ว +1

      okay, thank you.
      its full now

  • @sandipsuryawanshi4788
    @sandipsuryawanshi4788 ปีที่แล้ว

    Good

  • @akaradet5387
    @akaradet5387 ปีที่แล้ว +2

    ดี

  • @devidengo
    @devidengo ปีที่แล้ว

    Juluuiuuu 8:56 u

  • @darknessgamerz7505
    @darknessgamerz7505 ปีที่แล้ว

    nostalgia