5. Amortization: Amortized Analysis

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  • Опубликовано: 2 дек 2024

Комментарии • 49

  • @alexandrebrownAI
    @alexandrebrownAI 2 года назад +33

    Timestamps:
    - 0:20 : Introduction, Usefulness of Amortized Analysis
    - 1:41 : Table Doubling Problem with Intuition on Amortized Cost
    - 5:42 : Aggregate Method
    - 7:18 : General Definition of Amortized Bounds
    - 14:02 : Accounting Method
    - 22:22 : Table Doubling Problem using Accounting Method
    - 27:57 : Charging Method
    - 31:00 : Table Doubling Problem using Charging Method
    - 42:11 : Potential Method
    - 48:52 : Binary Counter Problem using Potential Method
    - 56:00 : Insert in 2-3 Trees using Potential Method
    - 1:04:21 Insert & Delete in 2-5 Trees using Problem Method

  • @emmafoley8987
    @emmafoley8987 4 года назад +22

    The best explanation of potential amortization I've found!

  • @imprsnt
    @imprsnt 8 лет назад +60

    Load Factor = number of Elements / Size of table = n / m.

    • @samiere
      @samiere 6 лет назад +1

      referencing @2:30

    • @dylancutler1978
      @dylancutler1978 6 лет назад

      I was wondering about that. In his analysis table doubling would have increased the runtime complexity, this makes more sense.

    • @alisalloum2005
      @alisalloum2005 3 года назад +1

      You saved my life

    • @Jayveersinh_Raj
      @Jayveersinh_Raj 3 года назад

      @@alisalloum2005 Helloo Buddy!! XD

    • @gshengelaia2001
      @gshengelaia2001 2 года назад +1

      so there is an error in the video right?

  • @DenisG631
    @DenisG631 7 лет назад +18

    11:51 But that's not entirely true, since you can "try" removing an item, which is not in the tree, which will still cost O(logN) in order to look for the item, which is missing.
    Correct me if I'm wrong

    • @MrLala12321
      @MrLala12321 7 лет назад +7

      It's possible the log(n) is referring to the rebalancing of the tree(which wouldn't happen if the element didn't exist) and not the searching for the element. Otherwise you're correct.

  • @rohitnagare7634
    @rohitnagare7634 2 года назад +6

    14:02 Accounting method

  • @pistachios2463
    @pistachios2463 4 года назад +15

    41:41 potential method

  • @forthrightgambitia1032
    @forthrightgambitia1032 4 года назад +2

    Interesting, I studied B-trees at uni and they presented the 2, 5 tree without justification of those numbers. But here it is.

  • @user-tk2jy8xr8b
    @user-tk2jy8xr8b 5 лет назад +6

    I got the idea of amortization in general, but these coins are totally weird. Why the heck do we charge back in time only once per insertion?

    • @junzhai1715
      @junzhai1715 3 года назад

      as long as the coin value is constant, O(1), it is fine, not necessary "once", could be 2,3,4...
      The point is that the cost of copying n elements charges 2 * n/2. we can save those n/2 coins with value 2 during each of the n/2 element's insertion.
      In contrast, we cannot save coins with value O(n), because that will make the insertion not O(1) anymore.

  • @hritikzurange
    @hritikzurange Год назад +1

    thanks for the charging method, makes life much easier :)

  • @puffvayne
    @puffvayne 2 года назад +2

    Potential Method 42:20

  • @ChadieRahimian
    @ChadieRahimian 7 лет назад +12

    This is the only data structure lecture of MIT, I didn't understand a word of :((

    • @ChadieRahimian
      @ChadieRahimian 7 лет назад

      I have. Even all the other lectures of 6.046.

    • @TroyWhorten
      @TroyWhorten 7 лет назад +1

      Chapter 17 from CLRS? The potential method in particular was pretty fuzzy for me from just the lecture but the description in the book really brought it together.

    • @ChadieRahimian
      @ChadieRahimian 7 лет назад

      Troy Whorten yeah I'm having a hard time understanding the concept of amortization. I guess I need to go through that chapter of the book couple more times 😁

    • @miro-miro-on-the-wall
      @miro-miro-on-the-wall 6 лет назад +27

      oof get out of here with your misogynistic bs

  • @avoriginal9342
    @avoriginal9342 6 месяцев назад

    so for the accounting method you are adding 2 coins for each insertion, 1 insertion costs 1 coin and you store one to be able to pay for the deletion?

  • @arno.claude
    @arno.claude 2 года назад +1

    11:08 why did he throw that frisbee? :D is it a reward for answering a question correctly? :D

  • @radred3662
    @radred3662 Год назад +2

    shoutouts to any students at uvic cramming for an exam right now

  • @JuanSanchez-yi1wn
    @JuanSanchez-yi1wn 4 года назад +1

    At 39:00 Can I use this for Crypto asset valuation? Specifically BTC since BTC white papers solves double spending problem

    • @bhavyagor5366
      @bhavyagor5366 2 года назад

      hey pls connect with me, i have a serious blockchain project to make

  • @AdamOwolabi-p2y
    @AdamOwolabi-p2y 13 дней назад

    This is so good.

  • @hossein_haeri
    @hossein_haeri 4 года назад +10

    Misleading words... Hard to get the core concept... I kinda think those people sitting there already knew the concept which is no surprise at MIT!

  • @chaitrakeshav
    @chaitrakeshav 3 года назад

    This is too good!

  • @thinkweb2
    @thinkweb2 5 лет назад +5

    I love Eric's explanations but this one felt way too theoretical. I wish he started with examples and used these techniques before diving into nitty gritty.

  • @puffvayne
    @puffvayne 2 года назад

    Why there are chalks on my face?

  • @jawoo2228
    @jawoo2228 Год назад

    huhuhhh, yeahhhhh... Mr Van Driessen's cool...

  • @ChrisLeeX
    @ChrisLeeX 7 лет назад +6

    25:15 Not the correct conclusion.

  • @shivanshpachauri2855
    @shivanshpachauri2855 3 года назад

    i feel Eric to be too less energetic in this video.

  • @sydneystriker5355
    @sydneystriker5355 5 лет назад +1

    The last lecture was so hard that this lecture seemed piece of cake. :)

  • @Sacheess
    @Sacheess 3 года назад +3

    51:44 does he give frisbees for answers? So fucking cool.

    • @LegolasSmith
      @LegolasSmith 3 года назад

      i think its like an "extra grade token"

  • @ChrisLeeX
    @ChrisLeeX 7 лет назад +6

    40:27 That example went nowhere.

  • @radhekrishanrathod9001
    @radhekrishanrathod9001 5 лет назад +1

    why they are not using marker

  • @volkankaln4713
    @volkankaln4713 3 года назад

    This lecture makes me smell chalk.

  • @luojihencha
    @luojihencha 4 года назад +2

    I feel I am so stupid...

  • @es8336
    @es8336 6 месяцев назад

    i dont understand shit i fucking hate computer science

  • @sudipandatta5371
    @sudipandatta5371 4 года назад

    this is the most boring lecture of mit