Top 5 Most Common Graph Algorithms for Coding Interviews

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  • Опубліковано 5 жов 2024

КОМЕНТАРІ • 73

  • @NeetCode
    @NeetCode  3 роки тому +21

    🚀 neetcode.io/ - I created a FREE site to make interview prep a lot easier, hope it helps! ❤

    • @DennisWanyonyi
      @DennisWanyonyi 3 роки тому

      Unfortunately VMv4 doesn't work when redeemed as a coupon

    • @eyekenspel1765
      @eyekenspel1765 2 роки тому

      @@DennisWanyonyi qqqqqq++q++qqqqq+qqq++qqqqq+++qqqqqqqqqqqqqqqqq11q+qq

    • @eyekenspel1765
      @eyekenspel1765 2 роки тому

      @@DennisWanyonyi q+qqqqqq++++q+qqq+q+qq+++qqqqqq1q++q+qqqqq+++++++++++++++

  • @shreddingstuff
    @shreddingstuff 3 роки тому +167

    Dude I sincerely can't thank you enough. I'm studying for job interviews and your content is the only reason I feel semi-confident going into them

  • @ishandeshpande4843
    @ishandeshpande4843 2 роки тому +100

    1) DFS
    2) BFS
    3) Union Find
    4) Topological Sort
    5) Dijkstra's Algorithm
    Bonus (Not as frequently asked)-
    1) Prim's/Kruskal's Algorithm (MST)
    2) Floyd Warshall's Algorithm

    • @jitendrakumar-vv8ho
      @jitendrakumar-vv8ho 2 місяці тому +1

      actually bonus has been asked in my interview round of algouniversity so it should be in important one and dijkstra is very much common and asked in interview

  • @amirnasser7768
    @amirnasser7768 9 місяців тому +7

    Thanks for the informative videos. Just a small correction about the time complexity of DFS and BFS: it is not O(V) where V is the number of nodes, but O(V+E), where you should consider the edges as well.

  • @UnspokenThings
    @UnspokenThings 2 роки тому +23

    Ur playlist is the reason I feel confident with Graph questions. Thanks Man!!

    • @technicalspot1848
      @technicalspot1848 Рік тому

      Hey i know bfs ,dfs topo,dijkstra but don't know Floyd warshall prim kruksal right now should i could follow neetcode graph playlists i am tired of just learning new algos i want to solve question to particular these algos after solving some questions i will move to others algos could you guide ?

  • @runfunmc64
    @runfunmc64 2 роки тому +70

    i think it’s pronounced dye-kstras algorithm btw

    • @MundoTecChannel
      @MundoTecChannel Рік тому +10

      🤓☝️

    • @rohitkumar-el9vi
      @rohitkumar-el9vi 8 місяців тому +3

      Witcher 3 also has a character named dijkstra.

    • @gnes04
      @gnes04 8 місяців тому

      Dyke straw lol

    • @AMX0013
      @AMX0013 Місяць тому

      Yea and they pronounce him dee 'k stra. After playing it, i always called it that calling others pronunciation as uncouth

  • @juda550
    @juda550 3 роки тому +49

    The time complexity of graph traversals is actually O(V + E), where V is the number of nodes, and E is the number of edges. Graph traversals are only (n) when the graph is a tree with a fixed amount of children(like a binary tree)

    • @anonymoussloth6687
      @anonymoussloth6687 3 роки тому +1

      Can u explain how it is V+E in detail?

    • @juda550
      @juda550 3 роки тому +9

      @@anonymoussloth6687 Hey sorry for responding kind of late, but think of the graph as an adjacency list/hash-map. If you want to traverse the entire graph, you need to traverse each key(vertex) and every value (edge). Therefore, the time complexity is O(V + E)

    • @simonchristian160
      @simonchristian160 2 роки тому +1

      JUDA FROM CSCAREERSDEV?

    • @juda550
      @juda550 2 роки тому

      @@simonchristian160 yessir

  • @ramvenkatachalam8153
    @ramvenkatachalam8153 4 місяці тому +1

    Only bez of Ur playlist is the reason i think i will get a good job . absolutely wonderful videos on DSA . I lov u bro.

  • @krige
    @krige 2 роки тому +18

    7:33 isn't topological sort actually identical to BFS?

    • @kyriakoskourkoulis1159
      @kyriakoskourkoulis1159 2 роки тому

      Yeah that's what I think as well🤔

    • @fsouza
      @fsouza 2 роки тому +7

      In that case yes, but because he picked a bad example.

    • @technicalspot1848
      @technicalspot1848 Рік тому +1

      Topo could be extended by both dfs and bfs(also called as khan's algo)

  • @yang5843
    @yang5843 2 роки тому +14

    Just fyi, the Di in Dijkstra is pronounced like Di in Dice
    Thanks for the video

    • @CST1992
      @CST1992 6 місяців тому

      Witcher 3 players would know

  • @mohithadiyal6083
    @mohithadiyal6083 3 роки тому +3

    It's a remainder that you are doing amazing 😁👍🏻

  • @tahichy9169
    @tahichy9169 2 роки тому +2

    Its really helpful that you categorize every problem and made a separate folder

  • @praveenmishra2470
    @praveenmishra2470 2 роки тому +5

    One of the best interview preparation channel

  • @abdoulbarry8111
    @abdoulbarry8111 2 роки тому +7

    Why isn't Top Sort BFS since it looks like you are doing level order traversal?

    • @SteversIO
      @SteversIO 3 місяці тому

      BFS + topological sort is more complex but feels more intuitive (to me).
      There's more code as you need to manage "in degrees" (the number of incoming edges to a node) and you need a queue (common in BFS).

  • @gamerclips8895
    @gamerclips8895 2 роки тому +28

    The algorithms were created for optimizing software, deliver efficient solutions, but nowadays most of the companies use them to filter out candidates in job interviews and look cool🤦🏽‍♀️, once you get into the company you probably are not going to hear about that never again

  • @ChristopherLoverich
    @ChristopherLoverich 2 роки тому +12

    Topological sort is IMHO less obscure than Union Find or Dijsktra's. The latter are more well known by name because they are illustrative for didactics, e.g. Union Find is the first major algorithm introduced in Sedgewick's book as a case study, before returning to a more orderly review of algorithms. Topological sort is, conversely, is an extenstion to a wide variety of well known practical problems like ordering a course schedule or execution of project or (automated) job dependencies. Cracking the Code Interview even argues you should be able to derive it on the spot if you didn't know it (I disagree but shrug). Its a minor point but I think people might see it and think they should study it last, where as IMHO its more expected knowledge than Dijkstra's and also really easy to understand once you've done a few DFS problems!

    • @musilicks
      @musilicks Рік тому +1

      damn bro you really are just talkin. Power to u brudder

  • @heen1211
    @heen1211 Рік тому

    Because of your content..I feel confident while giving interview...huge respect❤

  • @edgarcamelo3472
    @edgarcamelo3472 2 роки тому +1

    What about Bellman Ford or Floyd Warshall Algo

  • @anonymoussloth6687
    @anonymoussloth6687 3 роки тому +7

    Shouldnt topological sort use bfs? Since we would have to print all nodes that are at the same level or depth before going further?

    • @NeetCode
      @NeetCode  3 роки тому +4

      Yeah you're right, I think most people do bfs, but I usually do it dfs which is more simple imo (I used dfs for the alien dictionary problem)

  • @aaen9417
    @aaen9417 Рік тому

    this content is gold, man

  • @reginafadeeva7881
    @reginafadeeva7881 2 роки тому

    You are the best! Thank you soooo much)

  • @a2xd94
    @a2xd94 Рік тому

    Great set of problems! Are the problems sorted in order of importance/frequency encountered (IE DFS most important/frequent, Djikstra's algo least important/frequent)?

  • @harryz7973
    @harryz7973 3 роки тому +1

    would highly appreciate if you can solve 636. Exclusive Time of Functions

  • @amitvyas7905
    @amitvyas7905 2 роки тому

    At 5:22 you say "which is how I was taught" so could you let us know who taught you and how you started to come up with these approaches to solve all these problems?

  • @zifanxu522
    @zifanxu522 3 роки тому

    Nice topic! Thanks

  • @adnanelouadghiri6880
    @adnanelouadghiri6880 Рік тому

    We need a video for LeetCode 1319!

  • @kotsios1998
    @kotsios1998 2 роки тому

    time complexity of dfs isn't O(V+E)?

  • @tirupatirao7521
    @tirupatirao7521 2 роки тому +2

    Why so less subscribers dnt know

  • @daydrivver2074
    @daydrivver2074 2 роки тому

    You mention a lot hashset is there any video recommended to learn about that data structure? Most focus on implementation

  • @ramesh_hegde
    @ramesh_hegde 2 роки тому +1

    hello everyone,, lets write some neetcode today.

  • @hpj1992
    @hpj1992 2 роки тому

    What about bellman ford's algo? Not so common?

  • @technicalspot1848
    @technicalspot1848 Рік тому

    I know bfs ,dfs,topo sort dijkasta and uninon find little bit too should i start solving questions ?

  • @pranavsharma7479
    @pranavsharma7479 2 роки тому

    upload more videos on graphs sir

  • @admirer.of.cinema9731
    @admirer.of.cinema9731 11 місяців тому

    Hi can any one help me here, I used to be python coder but got laid off in April and now I want to switch into more development side I am doing dsa only for sometime what other skill should i focus on

  • @hackytech7494
    @hackytech7494 3 роки тому

    Thankyou so much

  • @impatientgaming9868
    @impatientgaming9868 9 місяців тому

    Good One.

  • @tooovisibletosee
    @tooovisibletosee Рік тому

    Does topological sort use dfs or bfs? From explanation it’s describing bfs 😮

    • @tooovisibletosee
      @tooovisibletosee Рік тому

      @neetcode

    • @neilmehra_
      @neilmehra_ 6 місяців тому

      You can implement topo sort either way, doesn't really matter. Either use BFS, "remove" edges by subtracting indegrees on vertices and add when indeg[u] = 0, or just build the DFS tree.

  • @IYI_WOLF_IYI
    @IYI_WOLF_IYI Рік тому +1

    shouldn't topological sort be BFS and not DFS? (minor error?)

    • @neilmehra_
      @neilmehra_ 6 місяців тому

      You can implement topo sort either way, doesn't really matter. Either use BFS, "remove" edges by subtracting indegrees on vertices and add when indeg[u] = 0, or just build the DFS tree.

  • @huizhao2050
    @huizhao2050 2 роки тому

    Hello, for the generic DFS method, should we use void or returning something?

  • @CEOofTheHood
    @CEOofTheHood 3 роки тому

    LEGEND!!!

  • @ExamSolutions_et
    @ExamSolutions_et 2 роки тому

    thank you . and I would like to see your face

  • @shankar7435
    @shankar7435 Місяць тому

    Dijkstra in school??? Noway...😂😂😂

  • @BBRR442
    @BBRR442 Рік тому

    i only hear mouth sounds on this video....