Binary Search Algorithm Explained (Full Code Included) - Python Algorithms Series for Beginners

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  • เผยแพร่เมื่อ 21 ก.ย. 2024

ความคิดเห็น • 132

  • @kiraisonline
    @kiraisonline ปีที่แล้ว +8

    Man I really wish you would bring this series back for other algo techniques, you are my fav python instructor on YT

  • @osvaldogarcia6154
    @osvaldogarcia6154 5 ปีที่แล้ว +54

    Thanks a lot for this videos man, they are so simple, but they explain everything in perfect detail

  • @MyLoweLife
    @MyLoweLife 3 ปีที่แล้ว +6

    You explained this like I'm 5 years old and thank you bc it makes perfect sense now 😭🙌🏾

  • @sechvnnull1524
    @sechvnnull1524 2 ปีที่แล้ว +2

    You are amazing! I just started my Data Structures and Algorithms course, and I almost had a heart attack as we covered both linear and binary search algorithms and now have to do math problem for the quiz. Both (0)logn and theta problems. But the most important thing is to understand the logic and what the code is doing. You're doing an awesome job at explaining this!! Thank you.

  • @hb5165
    @hb5165 ปีที่แล้ว +1

    I'm cramming for my first face-to-face technical interview in 2 weeks and I have to say that I wish I found your channel sooner. Thank you for your effort in making these videos.

    • @swarooprajpurohit110
      @swarooprajpurohit110 ปีที่แล้ว +5

      How did your interview go?

    • @bedi8049
      @bedi8049 ปีที่แล้ว

      @@swarooprajpurohit110 bro did not get hired

  • @teen_python_go9947
    @teen_python_go9947 2 ปีที่แล้ว

    Binary Search Implementation (I tried before seeing your approach):
    def binary_search(seq, val):
    print(f"Base Array: {seq}")
    seq.sort()
    print(f"Sorted array: {seq}")
    midpoint = len(seq)//2
    while seq[midpoint] != val:
    if val > seq[midpoint]:
    midpoint = midpoint + len(seq[midpoint+1:])//2
    elif val < seq[midpoint]:
    midpoint = len(seq[:midpoint])
    return f"value is at {midpoint} index in {seq}"

  • @jimrakel418
    @jimrakel418 4 ปีที่แล้ว +2

    Thank you for your videos. I came across your algorithm series this morning and spent the day watching all 5 videos and learning from your examples. Now I can use them to make my own Python library of tips & tricks to use when I program. Keep up the good work!

  • @msms3260
    @msms3260 4 ปีที่แล้ว +1

    You are sooooo young and smart. I feel so inadequate in regard to thinking capacity 😭. But your videos are amazing, please don’t stop!

  • @toby709
    @toby709 3 ปีที่แล้ว +2

    When I studying this using the below list :
    sequence_a = [1,2,4,5,6,7,8,9,12,14,16,17,22]
    list_a = 1
    it will return 0 as sequence, which looks a bit strange to me...so I add +1 to it, haha
    print(binary_search(sequence_a, list_a)+1)
    Btw, it's a good video! Thanks for teaching me!

    • @pieters286
      @pieters286 3 ปีที่แล้ว +1

      yes, the list is zero refrenced in code, thus one needs to add 1 again when printing out to natural world.

  • @nonserviam24
    @nonserviam24 2 ปีที่แล้ว +1

    For anyone wondering.
    This is a recursive solution.
    a = [1,2,3,4,5,6]
    def binarySearch(value, low, high, list):
    if low value:
    return binarySearch(value, low, middle-1, list)

    #here we need to check the upper half as the value is bigger than midpoint
    elif list[middle] < value:
    return binarySearch(value,middle+1, high, list)
    else:
    return f"Value {value} is not in the list!"

    print(binarySearch(6, 0, len(a),a))

  • @in-thegarden
    @in-thegarden 2 ปีที่แล้ว +2

    Thanks for the tutorials Derrick they are so easy to understand and well explained. I’m self learning Java and Python for the past three months and your videos are very helpful. Good Teacher.

  • @salvationprayerfellowship8899
    @salvationprayerfellowship8899 5 ปีที่แล้ว +8

    Thanks alot man for the tutorial very well explained you deserve more subs

  • @solomontaiwoabbaly
    @solomontaiwoabbaly 4 ปีที่แล้ว +4

    Thank you very much for this amazing video. I've been searching everywhere for this but there are too complex. But this one is...Schway!!😀

  • @ahyungrocks5509
    @ahyungrocks5509 6 หลายเดือนก่อน

    Excellent tutorial. Love the algorithm explanation at the end to re-iterate our understanding.

  • @murtazahonarpoor4252
    @murtazahonarpoor4252 4 ปีที่แล้ว +1

    You are doing a great job man. The videos are short, well explained and very easy to understand. Please keep posting.

  • @kockgunner
    @kockgunner ปีที่แล้ว +1

    For beginners like me, make sure that the while loop has a

  • @redachikhaoui1209
    @redachikhaoui1209 3 ปีที่แล้ว +6

    and also for midpint can be (start + end )//2

  • @GG-le8bq
    @GG-le8bq 2 ปีที่แล้ว

    Hey Derrick , this is the first time I came across your video and it is so articulate and lucid . I am already subscribing and looking forward to learn more from you .

  • @elijahlair
    @elijahlair 2 ปีที่แล้ว +1

    Really loved this. Simple and precise. Thanks

  • @hasnainali9295
    @hasnainali9295 2 ปีที่แล้ว

    Absolute clutch, as a comp sci student, you explained better than the teacher (no offence to teacher lol)

  • @defaltcm
    @defaltcm 4 ปีที่แล้ว +15

    Cannot tell if he is smiling or being held at gun point with those facial expressions lol. At times he seems forced other times he generally seems interested.

  • @zisistsatsos2509
    @zisistsatsos2509 4 ปีที่แล้ว +1

    I think this code is a little simpler:
    key=a #the_number_you_are_searching
    first=0
    last=len(L)-1
    pos=-1 #the_position_of_the_number
    while first

  • @UtkarshaB
    @UtkarshaB 4 ปีที่แล้ว +1

    keep uploading ...Nicely,Thoroughly explained...

  • @rajkumar.alagappan
    @rajkumar.alagappan 5 ปีที่แล้ว +5

    Why we should use the formula midpoint= (start+end-start)/2 instead of (start +end)/2 ?

    • @CodeWithDerrick
      @CodeWithDerrick  5 ปีที่แล้ว +1

      I think your solution would work fine too! I haven't tested so don't hold me too it though, haha. In my head I was just adding half of the remaining positions to the current beginning position to get the midpoint is why I wrote it that way

    • @rajkumar.alagappan
      @rajkumar.alagappan 5 ปีที่แล้ว

      @@CodeWithDerrick ☺️ thank you

    • @igorverevkin7709
      @igorverevkin7709 4 ปีที่แล้ว

      It does work indeed since your begin_index and end_index get new values on every iteration :)

  • @MrSatz99
    @MrSatz99 4 ปีที่แล้ว +2

    Thanks amazing it was!
    Please upload video on linear search also!

  • @juliannafotheringham7101
    @juliannafotheringham7101 2 ปีที่แล้ว

    Beautiful videos you angel, so clear and simple.Thank you!!!

  • @param8378
    @param8378 2 ปีที่แล้ว

    This solution is better than lead code selection

  • @mikesdailygaming
    @mikesdailygaming 4 วันที่ผ่านมา

    def binary_search(arr, target):
    low, high = 0, len(arr) - 1
    while low

  • @marioandresheviacavieres1923
    @marioandresheviacavieres1923 ปีที่แล้ว

    Thanks a lot for the series!! I watch it all

  • @gedtoon6451
    @gedtoon6451 หลายเดือนก่อน

    Your algorithm is not quite right. if sequence_a = [2, 4, 5, 6, 9, 9, 9, 10, 12, 13, 14] and item_a = 9 it will return index 5. It is generally accepted that binary search should find the first occurrence, which is 4. Can you correct this problem?

  • @ilyosbekkarshiboyev7134
    @ilyosbekkarshiboyev7134 2 ปีที่แล้ว +1

    Thanks a lot for this videos man

  • @ssengendonazil6985
    @ssengendonazil6985 2 ปีที่แล้ว

    i do node.js and php but u made it clear for as weel thanx

  • @mustafaa.4690
    @mustafaa.4690 3 ปีที่แล้ว

    Who else feels embarrassed? 🤣🤣
    Note: Really thank you for this content. It helped me a lot.

  • @raulsanchez4716
    @raulsanchez4716 3 ปีที่แล้ว

    Super clear explanation! Thank you so much.

  • @eZaFJDUBB
    @eZaFJDUBB 9 หลายเดือนก่อน

    The program as is returns None every time unless you purposely choose a midpoint equal to the value you're searching for

  • @6abriel9
    @6abriel9 4 ปีที่แล้ว

    Thanks man! excellent explanation, greetings from Argentina

  • @philmelancon915
    @philmelancon915 19 วันที่ผ่านมา

    Should this work with a sequence containing duplicate values? It isn't in my testing but I could just be wrong. Make item_a = 22 and perform the binary search on this sequence: sequence_a = [2,4,5,6,7,8,8,9,11,13,14,17,22,22,777]. It should return 12, but returns 13 (the index of the second instance of 22 in the sequence). Is this just a limitation that should be accounted for?

  • @kda_-uh3vj
    @kda_-uh3vj 4 ปีที่แล้ว +3

    2:52 hahaha bruh that glitch in your face, sorry but I can't help but laugh but laugh it off. Btw really good video, it helped me a lot ;)

    • @rebornpixelsproduction
      @rebornpixelsproduction 3 ปีที่แล้ว

      While coders where too busy focusing on the code, you was busy focusing on him yeh :)

    • @lackyyyy3098
      @lackyyyy3098 3 ปีที่แล้ว

      @@rebornpixelsproduction u should focus on english yeh :)

  • @JesusAlfredoHernandezOrozco
    @JesusAlfredoHernandezOrozco ปีที่แล้ว

    Great video and explanation!

  • @diegososa5280
    @diegososa5280 4 ปีที่แล้ว

    Thank you so much. Huge help.
    Subscribed

  • @emorgan8698
    @emorgan8698 5 ปีที่แล้ว +2

    Hey Derrick. Really enjoy your videos and I think is brilliant the animations you are now adding to the beginning of your videos to explain the theory. I'm trying to create a complexity matrix to determine how complex a project is based on user's input. Was thinking on using radio buttons or something similar for the user to select the input and then generate the result based on the selections. Any ideas on how best to accomplish this (it would need to be a web app)? I am new to Python. Do you think Django would work?

    • @CodeWithDerrick
      @CodeWithDerrick  5 ปีที่แล้ว +1

      Hey Eduardo! Thank you for the kind words! Sorry for the slow reply on this one. Django would definitely be able to handle it for you if you wanted to go down that route. You could collect the input using an HTML form, pass that to your view in django, do your calculations within your view, and then return it back to an HTML page. Django does take a bit of set up in the beginning, but once you get it running, there isn't really a limit to what you can do with it.
      If you decide to go down that route let me know if you get stuck anywhere - happy to make some tutorial videos around website creation!

    • @emorgan8698
      @emorgan8698 5 ปีที่แล้ว

      @@CodeWithDerrick thanks for your reply. if you could do some videos related to this idea that would be great. I'm not a developer so it can get tricky to get this up and running. I have some experience with RPGIV but I now work as Business Analyst. My idea is quite simple. have a table with rows and columns and allow users to select the options using radio buttons and show the risk level at the end. for both the radio buttons and the risk level I'm planning on using Bootstrap. in the meantime I'll keep trying and see how far I can get. keep up the good work and thanks for the help.

  • @yilu3219
    @yilu3219 2 ปีที่แล้ว

    why the midpoint is begin_index + ? why just second part ( end -begin)//2 only?

  • @priyanshudatta8845
    @priyanshudatta8845 ปีที่แล้ว

    you should cast as jack frost. ♥

  • @vlogiiidawidaaa7408
    @vlogiiidawidaaa7408 3 ปีที่แล้ว +1

    Is there going to be any more videos on algorithms? Great work!

  • @Rahdmi
    @Rahdmi 3 ปีที่แล้ว +1

    I can't figure out how to use binary search and user input. I want to use binary search to look at a list of names the user typed in , ask the user for a name to search and display if the name was there or not. I doubt you'll see this but I thought I would put it out there. Can anyone help me?

    • @meteerol8082
      @meteerol8082 3 ปีที่แล้ว

      @Mister Blo0 as he did, user could input the target as an argument in function

  • @saiyan5592
    @saiyan5592 6 หลายเดือนก่อน

    Bro pls post more videos on this datas and the algorithms pls ........................
    🙏🙏🙏🙏🙏🙏🙏🙏🙏🙏🙏🙏🙏🙏🙏🙏🙏🙏🙏🙏🙏

  • @TrueHumanNature74
    @TrueHumanNature74 4 ปีที่แล้ว

    def search(list,target):
    for item in list:
    if list[item]==target:
    print(i)
    list=[4,3,6,8,7,9]
    target=7
    search(list,target)
    4 #print the index where item belongs

    • @klejdisbeshi8768
      @klejdisbeshi8768 4 ปีที่แล้ว

      I think it should be if item == target... And this is not binary search so your comment is not valid.

  • @kelvin6335
    @kelvin6335 2 ปีที่แล้ว

    Great vid! tysm!

  • @methulidulanima5344
    @methulidulanima5344 3 หลายเดือนก่อน

    Thank you !

  • @selimtanrverdi9639
    @selimtanrverdi9639 3 ปีที่แล้ว

    Thanks a lot. Very great explanation.

  • @zakirhossain7413
    @zakirhossain7413 4 ปีที่แล้ว

    gracefully done!

  • @demrieanntinds
    @demrieanntinds 3 ปีที่แล้ว +2

    hello Derrick, I have a question. What if in the sorted list there is a duplicated number/ numbers? Thanks a lot! :)

    • @bolawolesegun4248
      @bolawolesegun4248 2 ปีที่แล้ว

      it will pick the first index of the located value

  • @kerolosgeorge-l5k
    @kerolosgeorge-l5k 10 หลายเดือนก่อน

    Derrick ,I just completed a python course ,however it is a basic one i am still finding myself rigid while coding how do they I can develop myself to a level where i can write codes smoothly?? Thanks

  • @wajdy2620
    @wajdy2620 ปีที่แล้ว

    im confused by the 7th line. Isnt beginning index always going to equal the same so then it would just cancel out? How could beginning index be 2 different values in the same line?

  • @soseofficial3923
    @soseofficial3923 2 ปีที่แล้ว

    very useful brother. thanks a lot.

  • @augusto.carmona
    @augusto.carmona 3 ปีที่แล้ว

    great videos man!

  • @jpchato
    @jpchato 3 ปีที่แล้ว

    Awesome, Thank you!

  • @adji97
    @adji97 3 ปีที่แล้ว

    thanks man this video helps alot

  • @Corrado49
    @Corrado49 3 ปีที่แล้ว

    thanks, really help me out!

  • @udaijitpattnaik4242
    @udaijitpattnaik4242 3 ปีที่แล้ว

    what do you actually mean by complexity?
    is it the time required for the p;rogram to run?
    if we use quick sort could you please how much time will the program take

  • @davlatbekkobiljonov911
    @davlatbekkobiljonov911 ปีที่แล้ว

    thank you

  • @AreeshaSiddiqui-zy7js
    @AreeshaSiddiqui-zy7js 3 ปีที่แล้ว

    please do a video on data structures and linked list too

  • @brainworkout7035
    @brainworkout7035 2 ปีที่แล้ว

    Is it wrong if I find the mid_point like:
    midpoint = (begin_index + end_index) // 2

  • @thishuman
    @thishuman ปีที่แล้ว

    Thank you :)

  • @Sun48100
    @Sun48100 3 ปีที่แล้ว

    Thanks, this is helpful.

  • @madushani6844
    @madushani6844 2 ปีที่แล้ว

    Please upload the vedios for Merge sort, shell sort & heap sort as well.🥺❤️

  • @shaharyarahmed5777
    @shaharyarahmed5777 3 ปีที่แล้ว

    i noticed a issue if you pass [1, 2, 3, 4, 5] as the sequence the while loop goes infinity

  • @Adam-gp3ij
    @Adam-gp3ij 2 ปีที่แล้ว

    Awesome

  • @josepha8415
    @josepha8415 2 ปีที่แล้ว

    Great video

  • @agesilausii7759
    @agesilausii7759 4 ปีที่แล้ว +1

    Thanks very good Explanation. Why not put
    middle = (begin + end)//2 ?
    Looks simpler. :)

    • @Change_Test
      @Change_Test 4 ปีที่แล้ว +1

      I stumbled on the answer to this in another video. For certain sizes of input arrays, begin+end can create an integer overflow in some programming languages, so adding the extra steps prevents integer overflow errors. I don't understand what that means, but apparently that's the reason for this format.

    • @agesilausii7759
      @agesilausii7759 4 ปีที่แล้ว

      paperfish113 really? Thats interesting. I think overflow is when a number is too big for computer memory to handle.

    • @lucasm4299
      @lucasm4299 2 ปีที่แล้ว +1

      @@agesilausii7759
      Yes and while (begin + end) may be overflow l, (end-begin) won’t be overflow

  • @armisol00
    @armisol00 5 หลายเดือนก่อน

    TY BRO

  • @nikhilparakh3251
    @nikhilparakh3251 3 ปีที่แล้ว

    Amazing!!!

  • @temik26
    @temik26 2 ปีที่แล้ว

    Perfect!

  • @shaharrefaelshoshany9442
    @shaharrefaelshoshany9442 3 ปีที่แล้ว

    wowww, super!!

  • @nupurjhankar6745
    @nupurjhankar6745 ปีที่แล้ว

    can you do merge sort video

  • @elisasee7538
    @elisasee7538 3 ปีที่แล้ว

    Hey for line 7 why can't it just be begin+end//2

  • @jingzhuang4168
    @jingzhuang4168 4 ปีที่แล้ว

    Thumbs up!

  • @storm_rising
    @storm_rising 4 ปีที่แล้ว +1

    nrb approves

  • @SEE.ME.N0.M0RE
    @SEE.ME.N0.M0RE 3 ปีที่แล้ว

    Thank you so much Derrick, I've been rewatching the playlist almost daily.
    I have a question: I've tested this on an unsorted list and it did find the index of the element I'm searching for,
    does this mean that this can work on an unsorted list as well?
    Many thanks!

    • @fareselamine8115
      @fareselamine8115 3 ปีที่แล้ว

      Binary assumes you already have a sorted list. If you know the list to start with is unsorted, run it through a sorting algorithm first.

  • @loop7210
    @loop7210 11 หลายเดือนก่อน

    program code not working properly.IS the code wrong guys ?

  • @TheGorilla58
    @TheGorilla58 4 ปีที่แล้ว +2

    It's something I was using by 1981 (When I started with CP/M and PDP11 and VAX sistems). What You are showing it'a the startig procedure of a binary search. What about duplicates? It was already used in 1957 (Peterson, William Wesley (1957). "Addressing for random-access storage". IBM Journal of Research and Development.). Finally, I think U studied well. Pls Read also "Moore School Lectures" from the University of Pennsylvania's Moore School It's an old 1946 Compendium. Here is the link en.wikipedia.org/wiki/Moore_School_Lectures

  • @marclim9304
    @marclim9304 3 ปีที่แล้ว

    my number is off by one position what should i do?

  • @mariobezuidenhoudt6695
    @mariobezuidenhoudt6695 4 ปีที่แล้ว +3

    midpoint = (begin_index + end_index)//2

  • @znpkami
    @znpkami 3 ปีที่แล้ว

    neat!

  • @pritam1366
    @pritam1366 3 ปีที่แล้ว

    which ide is used in this video

  • @tonymartin3738
    @tonymartin3738 3 ปีที่แล้ว

    How do you perform 1 through 300

  • @rinku4240
    @rinku4240 3 ปีที่แล้ว

    Hey Derrick Sherrill, your video is amazing. But I would request you to please don't speak so fast during the animation or during the explanation.

  • @shiili7699
    @shiili7699 4 ปีที่แล้ว

    excuse me, why should "begin" and "end" be assigned to "mid +1" and "mid-1" ?
    istead of just "mid"

    • @huzaim.22
      @huzaim.22 4 ปีที่แล้ว

      Beacause of index in position
      Hence +1 means after the mid and -1 is before the middle point

  • @Pmills9
    @Pmills9 3 ปีที่แล้ว

    I don't get what is the point of this? Why not just return the index of the target number? Wouldn't it be the same either way? This just seems like an overly complicated way to do that. Not bashing you or anything but I just don't see the point of all this extra code

  • @tareqmahmud3902
    @tareqmahmud3902 3 ปีที่แล้ว

    Umm, why am I getting TLE's?
    Time limit expired errors. :)

  • @rajivgardas2920
    @rajivgardas2920 2 ปีที่แล้ว

    I love you

  • @spamcocobutt3672
    @spamcocobutt3672 2 ปีที่แล้ว

    wut if you have an even amount of items

  • @yunkel
    @yunkel 5 ปีที่แล้ว +2

    👍

    • @storm_rising
      @storm_rising 4 ปีที่แล้ว

      do you play Minecraft?

  • @shahzan525
    @shahzan525 4 ปีที่แล้ว

    Make video on merge sort...... Really need it.....

  • @abdulrameez151
    @abdulrameez151 4 ปีที่แล้ว

    Is the code same for visual code for python on windows

    • @MegaKash786
      @MegaKash786 4 ปีที่แล้ว

      Abdul Rameez yes

    • @avalon4352
      @avalon4352 3 ปีที่แล้ว

      ofc. Visual Code is just an IDE. there is no difference in codes

  • @saviaggarwal8135
    @saviaggarwal8135 4 ปีที่แล้ว

    not working in pycharm. Help me!!

    • @Corrado49
      @Corrado49 3 ปีที่แล้ว

      check the indentations

  • @stilgarfifrawi7155
    @stilgarfifrawi7155 3 ปีที่แล้ว

    What does it feel like to be born with plastic surgery?

  • @tarzan8110
    @tarzan8110 4 ปีที่แล้ว

    I've tested all of the sites for free points and only GameCrook works.

  • @agsrf6479
    @agsrf6479 4 ปีที่แล้ว

    If I told you that I am lying to you right now, would I be saying the truth?

  • @boogiegames8755
    @boogiegames8755 ปีที่แล้ว

    #tafelpoten die de winkel kottenphark in de schappen heeft
    Tafelpoten = [30, 50, 70, 80, 85, 90, 100, 120, 150]
    Tafelpoten.sort()
    MaatVanKlant = int(input("Welkom bij meubelwinkel khottenphark, wij verkopen hier verschillende maten tafelpoten, wat is de maat tafelpoot die u graag wilt?"))
    #zorgt ervoor dat er binair gezocht wordt
    def binair_zoeken(lijst, maat):
    links = 0
    rechts = len(lijst) - 1
    while links 0:
    dichtstbijzijnde_maten.append(Tafelpoten[index-1])
    if index < len(Tafelpoten):
    dichtstbijzijnde_maten.append(Tafelpoten[index])
    if len(dichtstbijzijnde_maten) > 1:
    print(f"helaas is de maat {MaatVanKlant}cm niet beschikbaar. daarentegen zijn de maten {dichtstbijzijnde_maten} wel vergelijkbaar met de maat die u gekozen heeft")
    elif len(dichtstbijzijnde_maten) == 1:
    print(f"helaas is de maat {MaatVanKlant}cm niet beschikbaar. daarentegen zijn de maten {dichtstbijzijnde_maten[0]} wel vergelijkbaar met de maat die u gekozen heeft")
    else:
    print(f"helaas is de maat {MaatVanKlant}cm niet beschikbaar.")