How many ways are there to walk across a room?

Поділитися
Вставка
  • Опубліковано 28 лис 2024

КОМЕНТАРІ • 141

  • @iantoys4193
    @iantoys4193 2 роки тому +155

    I’m the guy from Batman who fart

    • @yellowmarkers
      @yellowmarkers  2 роки тому +35

      This is the truest comment I've ever had

    • @chasejohnson8326
      @chasejohnson8326 2 роки тому

      have stroke 💀

    • @mikec518
      @mikec518 2 роки тому +6

      the hero we needed but didn't deserve

    • @burrdid
      @burrdid Місяць тому +2

      why so serious?

    • @mekaindo
      @mekaindo Місяць тому

      I don't get anything.

  • @adiaphoros6842
    @adiaphoros6842 2 роки тому +348

    You can still allow for left and down movements while still having a finite number of paths. Just don’t count paths that intersect itself.

    • @kyyzh12
      @kyyzh12 2 місяці тому +4

      Genius

    • @brandonmack111
      @brandonmack111 2 місяці тому +55

      Or, in other words, don't add the direction rule, instead add a rule that you cannot pass over a previously visited square.

    • @kylesnotepic
      @kylesnotepic Місяць тому +4

      snake

    • @KevinLivian
      @KevinLivian Місяць тому +3

      @@brandonmack111 yes. I don’t see the issue

    • @Negreb25
      @Negreb25 Місяць тому +1

      I was literally thinking the same

  • @daper1015
    @daper1015 22 дні тому +44

    The best math videos begin with "Have you ever wondered x? No? But I did, here's what I found."

  • @syllabusgames2681
    @syllabusgames2681 2 роки тому +64

    That was an enjoyable mess. I was expecting this to turn into an analysis of A Star, but I’m glad to see you stayed on the math side instead. While building a multi-input function to solve some problem comes up a lot in programming, I don’t think I have ever seen it done in this manner: where the function ends up being a single mathematical structure.
    Out of the video I have seen this year, this might be the one I learned the most from since this is the first time I have seen someone build a summation series to solve a problem rather than to complete some proof where they already knew the answer ahead of time. This is probably a process I will end up using at some point, so thanks for that.
    A few notes:
    It sounds like you keep changing the distance you are from the microphone. I have a habit of doing that. My only fix was wedging my chair against my desk so I couldn’t move too far from the mic while recording. Not the best solution.
    2:40 It’s hard to read vertical text. Instead, write the text out to the side and add a leader line.
    6:17 I enjoyed the series of different applications for the path algorithm. I can tell you were messing with this problem for a while.
    12:20 The music is a bit loud in this section.
    I appreciate you just saying “this” instead of reading off a bunch of variables/equations.
    Over all, this was a pretty enjoyable video. Thanks for making it.

    • @yellowmarkers
      @yellowmarkers  2 роки тому +8

      I find it unorthodox that you learned more from this video than from videos made by people with actual mathematics education because I had practically no idea what I was doing here.
      About A*, I hadn't actually heard of it before you made this comment, but it appears to have applications related to which traversing method is the fastest, rather than finding every possible method. In most lattices described in this video, every path would have the same number of moves.

  • @Kavukamari
    @Kavukamari Місяць тому +92

    it's just 1, the correct way. what is that way you ask? look inside your heart, the answer was inside you all along.

    • @manjuegazos4672
      @manjuegazos4672 29 днів тому +10

      Just go in a straight line instead of frickin' zigzagging

    • @thegoldengood4725
      @thegoldengood4725 6 днів тому

      “the answer is left to the reader”

    • @drhabit
      @drhabit День тому

      answer inside me

  • @Amy-qv3oq
    @Amy-qv3oq 17 днів тому +13

    This music is making me feel like I'm on a surreal point-and-click adventure.

  • @tunafllsh
    @tunafllsh 2 роки тому +10

    All problems related to computational geometry are fun to watch. Because you can always have nice visualizations

  • @SusDoctor
    @SusDoctor 2 дні тому +2

    I sometimes think im crazy, but then i see a video like this and I remember im not insane.

  • @qoekeur
    @qoekeur 2 роки тому +14

    the graphics on this are really nice. great job sir

  • @KrasBadan
    @KrasBadan 2 роки тому +5

    You could allow moving backwards as long as it doesn't repeat. For example, if you stand on some square and go up, then the moment you return to that square you can't go up anymore.

  • @redpepper74
    @redpepper74 29 днів тому +6

    You can transform this problem into another more general problem: How many ways are there to travel across an acyclic directed graph? Here the graph’s vertices correspond to the floor cells, and an edge exists between any two adjacent cells, in the direction that you are allowed to go in.

  • @ba-it3xz
    @ba-it3xz 4 дні тому +1

    I got recommended this video a week ago and watched a third of it... I only stopped watching it because I realized that it related to my discrete structures course... I am now watching it through because it might be able to help me with a 15 point problem on my assignment in my discrete structures course.

    • @ba-it3xz
      @ba-it3xz 4 дні тому

      Update: I'm curled up in a little ball on my bed.

  • @QuantenMagier
    @QuantenMagier 2 роки тому +3

    Here is a nice followup question:
    How many shortest ways are there to move through a gridded rectangular room if you allow diagonal movements with a cost greater-equal one and less than two: 1=cost_horizontal=cost_vertical≤cost_diagonal

  • @qKitti
    @qKitti 2 роки тому +12

    Hey YM, it's been a while since we've talked but I just wanted to say your videos are amazing! I love the editing, transitions, special effects, and all the research that goes into them as well :) Even the music, especially the one that started at 10:01 were really good! GL on the contest :D

  • @ArtTheGamer
    @ArtTheGamer 2 місяці тому +6

    I just sat through a math lecture... and enjoyed it...

    • @yellowmarkers
      @yellowmarkers  2 місяці тому +1

      Thanks, I'll be making more of these and I'll be trying to make them even more entertaining

  • @jackfrederiksen7979
    @jackfrederiksen7979 2 роки тому +5

    Finally, I have found another who uses a dodecahedron in their profile picture! My search is at last complete.

  • @miguelcerna7406
    @miguelcerna7406 2 роки тому +6

    This is rough but in general it is correct and I hope it helps with your intuition.
    Suppose we have n numbers as: a_1,a_2, a_3, ..., a_k, a_(k+1), ... n and we want to choose k numbers out of these.
    We know that the total possible ways of ordering is n!
    And note that the total possible orderings of a_1, a_2, ...a_k, a_(k+1),...n is exactly k! What is left over is (n-k)! (n_choose_k)
    Conclusively. we have n! = k!(n-k)! (n_choose_k) ==> n!/k!(n-k)! = (n_choose_k)
    Cool video. Make more. =)

  • @DeoIgnition
    @DeoIgnition 2 роки тому +6

    Great video Quinn! You should really look into doing the CCC next year as I think you would do great at it (probably better than me lol) as most of the problems are similar to this and you already intuitively have a good understanding of how to solve these problems. Keep up the good work as well, this video was very well made, one of these will go viral I am telling you!

  • @StarlitWitchy
    @StarlitWitchy 11 днів тому

    For the first problem my intuition is basically that you'll be making 3 up moves and 6 right moves guaranteed. These moves can be arranged in 9! Different combinations with each up and right move being unique, and you can un-unique the up moves from each other by divinding by 3! And same for right moves by 6!
    A general solution for getting from one corner to the other in an X by Y rectangle is
    (X-1+Y-1)! /( (X-1)! (Y-1)! )
    This is the same as the pick 3 from 9 unordered equation which does make sense. If you put notes numbered 1-9 in a bag and pull out three and put all the up movements on the three numbers you pulled and the right movements on all the rest, thatX's mathematically equivalent ig?

  • @greatfate
    @greatfate 2 роки тому +3

    OMG I literally came across this problem in Project Euler!!!! I ended up solving it by realizing that the progression of the number of ways forms a pascal triangle and I already knew its relationship to binomial coefficients😅I'm so glad somebody made a vid about it!!!! Cool explanation btw ♥♥

  • @joshuathomasbird
    @joshuathomasbird 24 дні тому +8

    if we define walking across a room as entering a specific door and leaving through a specific door, then the route doesn't matter, and there's only one way to walk across a room.

  • @thesketch1794
    @thesketch1794 2 роки тому +5

    I liked the part where you walked across a room

  • @LeoStaley
    @LeoStaley 2 роки тому +3

    Gosh I am loving browsing this tag.

  • @brillum
    @brillum 15 днів тому +1

    the beepbox music really puts this all together

  • @kotowskiGames
    @kotowskiGames 10 днів тому

    When I saw the title, I was like "Dynamic programming maybe?", and I was right

  • @Iwontusethis255
    @Iwontusethis255 13 днів тому

    "Its 3 am, i should probably sleep"
    UA-cam recommended:

  • @mrsharpie7899
    @mrsharpie7899 21 день тому

    You sound like a younger, less gritty J.C. Denton in this, and I am here for it lol

  • @lexinwonderland5741
    @lexinwonderland5741 2 роки тому +1

    i just started the video but i already love the music

  • @Dannii_1
    @Dannii_1 8 днів тому

    1:39 “Does this look familiar?”
    My dumbass: Hehe yeah it’s minesweeper

  • @thedra9ongod
    @thedra9ongod 23 дні тому +1

    it’s that one bitburner contract

  • @cycloneentertainmentofficial
    @cycloneentertainmentofficial 6 годин тому

    it turns out the real only path was the friends we made along the way.

  • @sledzik1235
    @sledzik1235 2 роки тому +5

    Umm you forgot that center of mass can sometimes be outside of humans body so you inaccesible yelow squares are invalid at the corners becouse I could banana myself around the corner and my center of mass is in the wall

  • @GrimblyGoo
    @GrimblyGoo 5 днів тому +2

    14:00 how come, in the irregular grid, that 20 quadrilateral can move ⬇️ to the 32 one? It seems like that move only takes you further from the exit.

    • @mrzd3756
      @mrzd3756 2 години тому

      It can be argued that the center of the figure is closer to the end figure, specially since they shared a side that goes diagonally and it brings the figures closer when going down

  • @jotadiolynedicci3361
    @jotadiolynedicci3361 21 день тому

    It was really cool video ! I loved it ! Although, i thought you might extend it to a probability question : what's the probability of going to door using those restriction ?

  • @truejeffanderson
    @truejeffanderson 2 роки тому +3

    You could say that each step in the walk must be closer to the destination. A more general statement where right and up are used for example.
    Also, I wonder how hard it would be to try this rule: can not walk into a square which was previously occupied.

    • @truejeffanderson
      @truejeffanderson 2 роки тому

      What if there were no walls? You just had a source square and a destination square and you found the probability of steps to get from here to there. And then put no limit on the direction of travel.

  • @truejeffanderson
    @truejeffanderson 2 роки тому +3

    @5:45 the numerator is (l-w-2), but on the next slide it shows (7+4-2). Perhaps the negative width in the first slide is a typo?

    • @Numa369
      @Numa369 2 роки тому

      It's a typo that was dragged the whole video sadly, making the final función actually wrong

    • @yellowmarkers
      @yellowmarkers  2 роки тому +2

      I apologise for that typo, I will make a correction in the description to avoid getting more people misinformed. Thank you for letting me know about it

  • @LittleCloveredElf
    @LittleCloveredElf Місяць тому

    Dam I actually enjoyed this even with beforehand knowledge amazing soundtrack you earned a sub

  • @ameliasteynberg5841
    @ameliasteynberg5841 2 роки тому +1

    Really well-made video.

  • @moo4boy
    @moo4boy 2 роки тому +1

    Another way to solve would be with a recursive formula, it would be described as following assuming l and w are integers.
    f(l,w)=f(l-1,w)+f(l,w-1) l>1&w>1, 1 otherwise.

    • @MrHenryG123
      @MrHenryG123 Місяць тому +1

      Nice, that is the essence of how this is solved via Dynamic Programming

  • @janmae
    @janmae 2 роки тому +1

    Hey man, very clean, interesting and professional. Good sNice tutorialt.

  • @ayushanand_9a502
    @ayushanand_9a502 Рік тому +2

    What if we can go left or down but not go to an already visited square

  • @PretzelBS
    @PretzelBS 20 днів тому

    Everyone loves square and hexagonal tiling, but why doesn’t triangular tiling get any love??

  • @blockshift758
    @blockshift758 Місяць тому +1

    I was sure i have watched this before. And then the circle appeared

  • @sriramn1809
    @sriramn1809 5 днів тому

    Removing down and left movements kinda make it too simple.
    Just make it so u can only pass through 1 tile once. That wud be a better question to answer

  • @danielcajas7983
    @danielcajas7983 8 днів тому

    This is actually an interview question asked by google. Its quite hard to figure out in 30 minutes but yeah, its pretty much just dp

  • @chrisk6637
    @chrisk6637 12 днів тому

    KEEP NOTES GUYS! YOU NEVER KNOW WHEN NITENDO WILL PATTEN NEXT

  • @der.Schtefan
    @der.Schtefan 2 роки тому +1

    Have you considered submitting this as #SaME2 ?

  • @thacuber2a03
    @thacuber2a03 29 днів тому

    I thought you'd also try piecewise functions and recursion for the formula derivation

  • @kbeazy_3050
    @kbeazy_3050 9 днів тому +1

    5:42 I think the formula here has a typo

  • @zacknattack
    @zacknattack 20 днів тому

    was that stranded lullaby

  • @chasejohnson8326
    @chasejohnson8326 2 роки тому +1

    Please make more of these

  • @James2210
    @James2210 2 роки тому

    Definitely feels like a descent into madness meme

  • @rgc-exists
    @rgc-exists 7 днів тому +1

    Jonas Tyroller.

    • @rgc-exists
      @rgc-exists 7 днів тому

      (This is an inside joke that this person may or may not understand depending on if they are the same YellowMarkers I “interacted” with a long time ago)

    • @yellowmarkers
      @yellowmarkers  7 днів тому

      @@rgc-exists I am indeed the same person.

  • @ZedUndSonstNichts
    @ZedUndSonstNichts 2 роки тому +1

    And then you realize that the doors might not be on opposite walls but on the walls next to each other...

  • @jayrony69
    @jayrony69 8 днів тому +1

    Make the grid in planck lengths

  • @joshuabarqueesimeth4530
    @joshuabarqueesimeth4530 19 днів тому

    how many ways can you walk across the room, without any of the paths intersecting?

  • @truthseeker7815
    @truthseeker7815 2 роки тому +2

    "A human body has thickness"
    -some rule34 artist, probably

  • @LeoStaley
    @LeoStaley 2 роки тому +4

    I wish you would has extended it to getting accross a 3d lattice room.

    • @yellowmarkers
      @yellowmarkers  2 роки тому +3

      A 3d lattice would follow Pascal's pyramid instead of Pascal's triangle, and its formula would be (l + w + h - 3)!/((l - 1)!(w - 1)!(h - 1)!)
      Also, I recognise you from comments on some of David Pitcher's videos.

    • @LeoStaley
      @LeoStaley 2 роки тому +2

      @@yellowmarkers wooo! Niche nerdy youtube crew checking in!

  • @kuznechiks
    @kuznechiks 9 днів тому

    now find how many ways there are to walk across a room with different pentagons inside of it

  • @elrikcourtemanche2281
    @elrikcourtemanche2281 22 дні тому

    How about if we don't use a square grid and limit the angle that the path ça follow to be between 0 and 90 degrees?

    • @hakurou4620
      @hakurou4620 15 днів тому

      Thats an infinite amount of paths, similarly to if you kept splitting the square grid into smaller and smaller square grids (which approaches infinity, even if it has a discrete answer for any given grid)

    • @elrikcourtemanche2281
      @elrikcourtemanche2281 15 днів тому

      @hakurou4620 yes, it's an infinite amount of paths. I didn't think this through all the way but felt like there would be something to do there with calculus

  • @be78hk
    @be78hk 13 днів тому

    6:49 did nobody else notice that going to the top path would be longer than the bottom path

  • @Bozitico
    @Bozitico 14 днів тому

    Please link the music! I enjoyed it, it wasn't bad.

  • @johnchessant3012
    @johnchessant3012 2 роки тому +1

    very cool

  • @Jacko_hedgehog
    @Jacko_hedgehog 8 днів тому

    Sounds like beepbox in the background

  • @ten-faced-carrot
    @ten-faced-carrot 12 днів тому

    Me rn (Middle of the night, 2 exams coming up): *interesting*

  • @coolroblox12
    @coolroblox12 6 днів тому

    What about going over the room

  • @CoulterKawaja
    @CoulterKawaja 7 днів тому

    5:44 where are the absolute value signs?

  • @Enderguy57
    @Enderguy57 14 днів тому

    it's one way, diagonally

  • @Zcon18
    @Zcon18 12 днів тому

    1:19 Omgr Combinatorics

  • @eWosMrV
    @eWosMrV 4 дні тому

    Thinking is finited when you only think inside a box.
    Process to walk on the wall to walk out of the room with no roof to make it a 3d space*

  • @rismosch
    @rismosch Місяць тому

    when i saw the thumbnail i immediately thought pascals triangle

  • @Ed1414One
    @Ed1414One 5 годин тому

    Just do 2^(n+k-2)

  • @Albaraa
    @Albaraa 8 днів тому

    The area of the room

  • @Ultimaximus
    @Ultimaximus 11 днів тому

    This music is great, it feels like a descent into madness just like the video itself

  • @shappp1
    @shappp1 29 днів тому

    make the squares each a Planck length long to get the true number

  • @jakethewolfie119
    @jakethewolfie119 2 роки тому

    jan Misali would approve

  • @jamez6398
    @jamez6398 2 роки тому +1

    Infinite.

  • @Yutaro-Yoshii
    @Yutaro-Yoshii 2 роки тому +2

    now try version with all four moves but path can't collide with itself

  • @strawberryjim
    @strawberryjim 3 дні тому

    this is my autism interpreted into a youtube video

  • @Tmayhem
    @Tmayhem Місяць тому

    do i hear beepbox in the background?!?

  • @lawrdtv
    @lawrdtv 2 роки тому +1

    I started making soft recently, I was wondering if you wanna do any features.

  • @frendogel_1115
    @frendogel_1115 5 днів тому

    Why Am I Watching This At 1 Am

  • @krzysztofmiller3557
    @krzysztofmiller3557 2 роки тому +1

    nice

  • @Bald1_Bas1cs
    @Bald1_Bas1cs 4 дні тому

    Infinite

  • @chalkosis9739
    @chalkosis9739 2 роки тому +1

    Hi ym UwU

  • @JustBlack4
    @JustBlack4 11 днів тому

    a lot-
    edit: -of ways to get across a room

  • @charl10439
    @charl10439 29 днів тому

    23

  • @smashbrosgoat
    @smashbrosgoat 2 роки тому

    yellow marker

  • @daffa_fm4583
    @daffa_fm4583 2 роки тому

    have you improved your self esteem yet

    • @yellowmarkers
      @yellowmarkers  2 роки тому +3

      Yes. I no longer hate myself, and the excessive self-deprecation has mostly stopped

  • @rigel7252
    @rigel7252 2 роки тому +1

    6th

  • @keonscorner516
    @keonscorner516 Рік тому

    tra

  • @SovietSpunge537
    @SovietSpunge537 2 роки тому

    Stop liking grounding countries

  • @NotSomeJustinWithoutAMoustache
    @NotSomeJustinWithoutAMoustache 2 роки тому +2

    I really love the music! Where can I listen to them? If you don't want others hearing it you can just send me an unlisted video link to the bgms then delete it after I get the link (I'll message you when I see the link) or I can contact you via discord/gmail or smth and you can just send the music files to me there, thanks!

    • @yellowmarkers
      @yellowmarkers  2 роки тому

      I might make a separate video compiling all of the music used in these videos, I'm just too lazy to do it right now