[Discrete Mathematics] Vertex Degree and Regular Graphs

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  • เผยแพร่เมื่อ 11 ก.ค. 2024
  • Today we look at the degree of a vertex and check out some regular graphs.
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ความคิดเห็น • 34

  • @utkuQ7
    @utkuQ7 6 ปีที่แล้ว +40

    you are an angel for a computer science student

  • @qandos-nour
    @qandos-nour 3 ปีที่แล้ว

    Thank you, your explanation is very clear and easy to understand

  • @mehakjain4402
    @mehakjain4402 6 ปีที่แล้ว +6

    Thank You for the discrete mathematics playlist. It's so damn helpful! I love it!
    Do you have a video which covers vertices degrees of directed graphs??

  • @aryansaxena4978
    @aryansaxena4978 ปีที่แล้ว

    thank you so much brother, this is one hell of a help

  • @johnherbert1321
    @johnherbert1321 6 ปีที่แล้ว +18

    dude why does this make so much sense when the textbook reads like I found a mandarin translation to create the Philosopher's Stone? ( For those that can read both English and Mandarin, sub in cuneiform or some equally difficult language to read)

    • @julr89
      @julr89 4 ปีที่แล้ว +3

      My textbook about Fundamentals of Computer Science has so many weird terms, I feel like I'm summoning a demon when I'm reading it lmao

  • @maxinec2325
    @maxinec2325 8 ปีที่แล้ว +1

    thank you very helpful

  • @poojithanarra6343
    @poojithanarra6343 3 ปีที่แล้ว

    Consider an undirected graph G that has n distinct vertices where each vertex has degree 2. Assume n≥3. What is the maximum number of circuits that G can contain? If all the vertices of G are contained in a single circuit, what is the maximum number of vertices that can be contained in an independent set?

  • @farrukhsaif108
    @farrukhsaif108 2 ปีที่แล้ว +1

    on around 15:50 , you assume that the odd degree vertices have the same value, which is not the case.

  • @kasyapdomakonda7678
    @kasyapdomakonda7678 2 ปีที่แล้ว

    Can u please mention the video number which helps us to see full chapter one after the other ?

  • @akaris8042
    @akaris8042 3 ปีที่แล้ว

    Thank you for this wonderful videos .
    With your knowledge of Discrete Mathematics am sure you know so much about Database Management System or Networking.
    If you do, please also make some videos teaching them .
    I left Maths like almost 14 years after ago and your channels has really been helpful to me since last 2018.

  • @TheEnigma7111
    @TheEnigma7111 7 ปีที่แล้ว +11

    Did you fail to mention that it is called handshake theorem or have you mentioned it somewhere else?

  • @saketkumar4972
    @saketkumar4972 10 หลายเดือนก่อน

    what does odd no. of odd degrees even mean

  • @the.polymath
    @the.polymath 3 ปีที่แล้ว +1

    In the part about hypercubes, I think that you accidentally added one to each binary number; it's actually 0 through 7, not 1 through 8.

  • @ariellelasry9459
    @ariellelasry9459 5 ปีที่แล้ว +6

    Question!! At 17:38 how come the +(2l) is part of the equation? what does degree remaining imply? I was able to do the same proof without that term because everything still works the same. I am just uncertain what that term represents? The first term (2k+1) is an odd number of vertices and the second term (2j+1) is the odd degree so I do not get what I'm missing. Thank you in advance!

    • @MichaelLee-sb3du
      @MichaelLee-sb3du 5 ปีที่แล้ว +1

      His mathematics for that question is just wrong

    • @MichaelLee-sb3du
      @MichaelLee-sb3du 5 ปีที่แล้ว +1

      Because the no. of vertices (which are odd 1,3,5 etc) x degree of odd vertices gives the total degrees from odd vertices. But he's assumed that all vertices have an odd degree which they don't because in an odd number of vertices there is both odd and even degree vertices. Then he goes on to add the number of degrees from the even vertices, the equation is just wrong

    • @ankurc
      @ankurc 5 ปีที่แล้ว

      In a graph, there can be both even and odd degree vertices. He assumes that there are odd number of odd degree vertices which you understood. There might also be even degree vertices which the 2*l represents.

    • @ankurc
      @ankurc 5 ปีที่แล้ว

      @@MichaelLee-sb3du I was also confused at first but I watched another video and then I understood.

    • @Mohammed24441
      @Mohammed24441 4 ปีที่แล้ว +2

      His equation is not rigorous.
      Suppose:
      n: be the number of all vertices
      2m + 1: be odd vertices number
      n - (2m + 1): the remaining (even) vertices
      So, now we will divide the degrees into two categories, even and odd. Since we want to proof by contradiction, then we want to show that a graph can have an odd number of odd-degree vertices.
      Given the equation: sum( deg(Vi) ) = 2 |E|
      such that i: vertex degree from 1 to n
      We can rewrite it as: sum( deg(Vi) ) + sum( deg(Vj) ) = 2 |E|
      such that Vi: is the ith vertex odd-degree, i: from 1 to (2m+1)
      and Vj: is the jth vertex even-degree, j: from 1 to (n - (2m + 1))
      From the original equation, we know that the left-hand side of the equation should evaluate to even. Since the sum( deg(Vi) ) is odd (since the sum of odd value (2m + 1) time evaluates to an odd value ), then sum( deg(Vj) ) has to be odd as well because odd + odd will evaluate to even which is not the case, because the second summation is the sum of even values which evaluates to even, hence the LHS = odd + even = odd which contradict with the RHS = even, hence a proof by contradiction that a graph cannot has an odd number of odd-degree vertices.

  • @sperera5916
    @sperera5916 7 ปีที่แล้ว +1

    What is the degree of a loop in a directed graph? Is it 1? Thanks

    • @sperera5916
      @sperera5916 7 ปีที่แล้ว

      maybe InDegree=1 and OutDegree=1? What is the total number of degrees then? Does that question make sense? Thanks

    • @Trevtutor
      @Trevtutor  7 ปีที่แล้ว +2

      Deg = Sum(id) + Sum(od), so each loop adds 2 degrees overall.

  • @mohdasifkhan2889
    @mohdasifkhan2889 5 ปีที่แล้ว

    Does deg ^- (v) mean odd
    and deg ^+ (v) mean even?

  • @wendya2309
    @wendya2309 6 ปีที่แล้ว

    "in a simple graph, must every vertex have degree that is less than the number of vertices in the graph"

  • @het314
    @het314 4 ปีที่แล้ว +2

    Wish me luck for my "degree" : |

  • @BerkeBoz
    @BerkeBoz 6 ปีที่แล้ว +1

    5:38 So savage :(

  • @tyche6955
    @tyche6955 9 หลายเดือนก่อน

    Why tf is my thingy not thingying