Breadth-first search in 4 minutes

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  • เผยแพร่เมื่อ 8 มิ.ย. 2024
  • Breadth-first search in 4 minutes.
    Code: github.com/msambol/dsa/blob/m...
    Sources:
    1. Introduction To Algorithms, Third Edition (CLRS) [www.amazon.com/Introduction-A...]
    2. en.wikipedia.org/wiki/Breadth...
    LinkedIn: / michael-sambol

ความคิดเห็น • 79

  • @MichaelSambol
    @MichaelSambol  ปีที่แล้ว +20

    After I made the video, I changed the code in GitHub to use a deque instead of an array for the queue. This allows us to pop the first element in 0(1) time. More here: wiki.python.org/moin/TimeComplexity.

  • @leonh2140
    @leonh2140 ปีที่แล้ว +75

    I love that your slides are so minimalistic, for me it's the perfect amount of content to support what you say

  • @adhoc3018
    @adhoc3018 2 ปีที่แล้ว +30

    It's good to see that you are back. Your past videos have helped me a lot, thank you.

  • @Hydrus_
    @Hydrus_ 2 ปีที่แล้ว +29

    I have an algorithm test coming up on graphs and this came out at exactly the right time! Thank you!!

  • @amaegbutah5957
    @amaegbutah5957 ปีที่แล้ว +3

    You are literally saving my life! I’m so glad that you’re uploading again!!

  • @mey1823
    @mey1823 2 ปีที่แล้ว +4

    Thank you for your quick illustrations! I enjoy your videos a lot.

  • @servantofthelord8147
    @servantofthelord8147 5 หลายเดือนก่อน +3

    Wow, you've added so much value in such a short amount of time. Thank you sir!

  • @kevincaballero6133
    @kevincaballero6133 ปีที่แล้ว +2

    Great video. Makes the concept very easy to understand. Thank you for the way you made it.

  • @cloyyd2227
    @cloyyd2227 2 ปีที่แล้ว +1

    your videos keep me sane i swear

  • @guirck
    @guirck 9 หลายเดือนก่อน +5

    That is so concise! Perfectly explained!

  • @dr.walidsoula
    @dr.walidsoula 2 ปีที่แล้ว +1

    You deserve more views, thank you for your videos

  • @JK-ls8kh
    @JK-ls8kh 2 ปีที่แล้ว +3

    you are literally helping me to survive my exam :) big thanks

  • @mihailtrajkoski1774
    @mihailtrajkoski1774 4 หลายเดือนก่อน

    Damn because of your videos, I managed to prepare for the exam tomorrow. I had no idea how I was going to get through so much material in one day, thank you.

  • @smikkelbeer7890
    @smikkelbeer7890 ปีที่แล้ว

    Clear and straight forward. Thank you.

  • @ezio9595
    @ezio9595 ปีที่แล้ว

    very useful and straight to the point, it was useful thanks!

  • @user-kp3ox6cc9k
    @user-kp3ox6cc9k 5 หลายเดือนก่อน

    Best Explanation on youtube so far..Every other video is from 15 to 20 minutes..and here you are doing it in 4 minutes😂

  • @RownitaTasneem-qf5sr
    @RownitaTasneem-qf5sr ปีที่แล้ว

    This video is well-explained.Thanks a lot for this ....

  • @brandoncazares8452
    @brandoncazares8452 ปีที่แล้ว

    Thanks, you literally saved my life.

  • @lennyb.9616
    @lennyb.9616 หลายเดือนก่อน

    thank you so much for explaining this in less than 5 min

  • @Motivational-Mango
    @Motivational-Mango 2 หลายเดือนก่อน +1

    I learned more in 4 minutes than all the 30 years of my life

  • @Jeetuni
    @Jeetuni ปีที่แล้ว +4

    Michael Sambol should take the place of my tenured professor that teaches Algorithms.

  • @victorkoroshilov9015
    @victorkoroshilov9015 2 ปีที่แล้ว +1

    This man does not miss 🔥

  • @NoOne-ev3jn
    @NoOne-ev3jn ปีที่แล้ว +3

    The Queue in place always go over my head, now with the visualisation it makes it a lot more easier and obvious 😅😅😅

  • @user-jf6dd2iy2s
    @user-jf6dd2iy2s 20 วันที่ผ่านมา

    Dude you are the best, cheers

  • @kafychannel
    @kafychannel ปีที่แล้ว +1

    thank you so much for clear explanation

  • @mateoldnsk2693
    @mateoldnsk2693 3 หลายเดือนก่อน

    You saved my entire life. Thank you so much.

  • @crazycroze
    @crazycroze ปีที่แล้ว +1

    Legit the best explanation out there.

  • @QuackDocElias
    @QuackDocElias 2 หลายเดือนก่อน

    thank you, so much easier to understand

  • @divelix2666
    @divelix2666 ปีที่แล้ว +2

    Why do you need "visited" queue? It can still work without it, doesn't it?
    UPD: just figured out that your algorithm is for general graph, but you apply it to a tree (special case of graph) so "visited" is redundant for tree case.

  • @nightshocker03
    @nightshocker03 11 หลายเดือนก่อน

    Ive been using recursion in dfs thinking it would work here too
    Thank you for helping me realize my mistake

    • @MichaelSambol
      @MichaelSambol  11 หลายเดือนก่อน +1

      Def easier iteratively for BFS! github.com/msambol/youtube/blob/master/search/breadth_first_search.py

  • @isabelcerdan4128
    @isabelcerdan4128 8 หลายเดือนก่อน

    Thank you for this videos

  • @jefferson5773
    @jefferson5773 ปีที่แล้ว

    thank you for your clear explanation

  • @marianpascu8474
    @marianpascu8474 ปีที่แล้ว

    Bro, you are a god of explaining and teaching, so quick, so simple, so smart, not like other teachers who sound like broken records and x2 speed you tube videos.

  • @jawadhaidar3931
    @jawadhaidar3931 5 หลายเดือนก่อน

    Thank you for the vide! What is the addrd value of the last if statement

  • @hellogais2177
    @hellogais2177 3 หลายเดือนก่อน +2

    You say first in first out like we are supposed to know where you put elements in and out, can't you put them in either at the top or at the bottom? And why do you say vertically and horizontally without showing a tree, the orientation can be different, we have to fast forward to see what tree you have in your mind, but we can't read yours

  • @frederiquebaaij
    @frederiquebaaij 2 ปีที่แล้ว +1

    Could you please make a video on the Hungarian Method for a bipartite graph, using only the graph? Or is this not a subject you can cover?

  • @kvelez
    @kvelez 6 หลายเดือนก่อน

    Great.

  • @misterawkward930
    @misterawkward930 6 หลายเดือนก่อน

    i love you so much and i hope you live a long happy life

  • @isimbulamadmobenibulsun660
    @isimbulamadmobenibulsun660 10 หลายเดือนก่อน

    ty very muchh

  • @arjunyonzan8557
    @arjunyonzan8557 ปีที่แล้ว

    Thanks

  • @kristofkatona2188
    @kristofkatona2188 7 หลายเดือนก่อน

    great video my

  • @f.u.spammers3846
    @f.u.spammers3846 ปีที่แล้ว +1

    Why not make "visited" a property of the node object so you don't have to create a separate 'visited' array?

    • @headyshotta5777
      @headyshotta5777 ปีที่แล้ว +4

      what if you have to run more than one search on the same set of nodes? you would have to traverse the entire tree twice to reset your nodes for a single search. with an array you can just clear it. Much easier.

  • @jaironicolasgomez1349
    @jaironicolasgomez1349 ปีที่แล้ว

    I love you!

  • @danielkerber8761
    @danielkerber8761 ปีที่แล้ว

    you mentioned the use of queue, but used a stack with pop function, no?

    • @MichaelSambol
      @MichaelSambol  ปีที่แล้ว

      The concept is the same where the abstract data structure is a queue, i.e., FIFO. In the video I used an array and did pop(0), but I later switched the code to use deque and popleft() [same concept as pop(0)] because it's more efficient. See here: github.com/msambol/youtube/blob/master/search/breadth_first_search.py#L17-L19.
      Let me know if that doesn't make sense!

  • @cupofjava5480
    @cupofjava5480 ปีที่แล้ว

    1:31 isn't the que popping 'C' first ?

  • @dannggg
    @dannggg 2 ปีที่แล้ว +1

    would be easier if you add what is the front and what is the end of the queue because other examples and other i see the queue is other way. I mean it doesn't matter since i figured it out after a few minutes but i think it would make it easier to understand quickly whats happening lol

    • @MichaelSambol
      @MichaelSambol  2 ปีที่แล้ว +1

      I should have added that, you're right. Apologies!

    • @dannggg
      @dannggg 2 ปีที่แล้ว

      @@MichaelSambol no worries just reviewing for algorithms test tomorrow And this really did helped me. Thanks for making these videos!!!

  • @kdewanik
    @kdewanik ปีที่แล้ว

    Respect 🫡

  • @Nico1a5
    @Nico1a5 หลายเดือนก่อน +1

    And what are you searching for in there?

  • @ramyakavyar
    @ramyakavyar ปีที่แล้ว

    Hi, the audio is not clear on your videos. It goes on mute in between for a few seconds. Could you please fix this on all your videos. It would be really helpful. Thanks.

    • @MichaelSambol
      @MichaelSambol  ปีที่แล้ว

      Sorry about that. I'm working on the right settings. Thanks for the feedback.

    • @MichaelSambol
      @MichaelSambol  ปีที่แล้ว

      Is my latest video better, on Fibonacci heaps?

    • @ramyakavyar
      @ramyakavyar ปีที่แล้ว

      @@MichaelSambol Nope. It isn't any better. Fibonacci heaps also has the same issue.

  • @Xolomilco
    @Xolomilco 3 หลายเดือนก่อน

    Confusing how you pop the [0] element yet you show that element as being on the far right of the array order, which would not be the [0] element in actual code...

    • @MichaelSambol
      @MichaelSambol  3 หลายเดือนก่อน

      Sorry that's confusing! Check the latest code here, I hope it clarifies it: github.com/msambol/dsa/blob/master/search/breadth_first_search.py.

  • @tutaf
    @tutaf 2 หลายเดือนก่อน

    Muhammad Sumbul 😳😳

  • @danielkim7024
    @danielkim7024 28 วันที่ผ่านมา

    What happens if the graph in question contains cycles? If we're marking nodes as visited when we pop them, won't that mean there will be multiple instances of a node being enqueued into the queue until they are actually reached and dequeued i.e. marked visited?

  • @WhiteFontStudios
    @WhiteFontStudios 7 หลายเดือนก่อน +46

    My lord. Sometimes play back speed 2x just isn't enough

    • @bitwodeddemissie7955
      @bitwodeddemissie7955 3 หลายเดือนก่อน +2

      Use revanced there is 5x

    • @legolorian3271
      @legolorian3271 หลายเดือนก่อน +12

      Maybe stop watching tik tok so you have an attention span longer than a minute

    • @NippieMan
      @NippieMan หลายเดือนก่อน

      @@legolorian3271 he does talk pretty slow I won’t lie.

  • @amirhoxha6231
    @amirhoxha6231 ปีที่แล้ว

    o nanq

  • @velerus3620
    @velerus3620 2 ปีที่แล้ว +1

    First

  • @ogolasaura1805
    @ogolasaura1805 8 หลายเดือนก่อน

    you code has issues i think this is the right way for BFS
    def bfs(graph, node):
    visited = []
    queue = []
    visited.append(node)
    queue.append(node)
    while queue:
    s = queue.pop(0)
    print(s, end=" ")
    for n in graph[s]: # Corrected indentation
    if n not in visited:
    visited.append(n)
    queue.append(n)

    • @MichaelSambol
      @MichaelSambol  8 หลายเดือนก่อน

      Definitely a few different ways to do it. See here: github.com/msambol/dsa/blob/master/search/breadth_first_search.py

  • @yuezhang8313
    @yuezhang8313 ปีที่แล้ว

    Thanks for your clear explanation