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

[@kiraisonline]

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

[@MyLoweLife]

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

[@sechvnnull1524]

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.

[@nonserviam24]

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))

[@hb5165]

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]

How did your interview go?

[@bedi8049]

@@swarooprajpurohit110 bro did not get hired

[@osvaldogarcia6154]

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

[@teen_python_go9947]

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}"

[@in-thegarden]

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.

[@jimrakel418]

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!

[@kockgunner]

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

[@ahyungrocks5509]

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

[@msms3260]

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]

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]

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

[@redachikhaoui1209]

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

[@salvationprayerfellowship8899]

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

[@param8378]

This solution is better than lead code selection

[@zisistsatsos2509]

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

[@murtazahonarpoor4252]

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

[@solomontaiwoabbaly]

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!!😀

[@elijahlair]

Really loved this. Simple and precise. Thanks

[@rajkumar.alagappan]

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

[@CodeWithDerrick]

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]

@@CodeWithDerrick ☺️ thank you

[@igorverevkin7709]

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

[@GG-le8bq]

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 .

[@ilyosbekkarshiboyev7134]

Thanks a lot for this videos man

[@marioandresheviacavieres1923]

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

[@hasnainali9295]

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

[@philmelancon915]

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?

[@mikesdailygaming]

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

[@juliannafotheringham7101]

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

[@ssengendonazil6985]

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

[@eZaFJDUBB]

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

[@MrSatz99]

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

[@JesusAlfredoHernandezOrozco]

Great video and explanation!

[@TrueHumanNature74]

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]

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

[@UtkarshaB]

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

[@kerolosgeorge-l5k]

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

[@gedtoon6451]

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?

[@raulsanchez4716]

Super clear explanation! Thank you so much.

[@defaltcm]

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.

[@CodeWithDerrick]

😂😂

[@demrieanntinds]

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

[@bolawolesegun4248]

it will pick the first index of the located value

[@wajdy2620]

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?

[@AreeshaSiddiqui-zy7js]

please do a video on data structures and linked list too

[@yilu3219]

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

[@emorgan8698]

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]

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]

@@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.

[@mustafaa.4690]

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

[@vlogiiidawidaaa7408]

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

[@shaharyarahmed5777]

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

[@6abriel9]

Thanks man! excellent explanation, greetings from Argentina

[@soseofficial3923]

very useful brother. thanks a lot.

[@Rahdmi]

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]

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

[@zakirhossain7413]

gracefully done!

[@diegososa5280]

Thank you so much. Huge help. Subscribed

[@josepha8415]

Great video

[@augusto.carmona]

great videos man!

[@jpchato]

Awesome, Thank you!

[@saiyan5592]

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

[@brainworkout7035]

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

[@madushani6844]

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

[@selimtanrverdi9639]

Thanks a lot. Very great explanation.

[@Corrado49]

thanks, really help me out!

[@adji97]

thanks man this video helps alot

[@agesilausii7759]

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

[@Change_Test]

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]

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

[@lucasm4299]

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

[@elisasee7538]

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

[@Sun48100]

Thanks, this is helpful.

[@priyanshudatta8845]

you should cast as jack frost. ♥

[@BiblicalArchaeologyAR]

Thank you!!

[@nupurjhankar6745]

can you do merge sort video

[@kelvin6335]

Great vid! tysm!

[@Rookiwi]

Thanks man

[@marclim9304]

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

[@loop7210]

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

[@TheGorilla58]

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

[@tonymartin3738]

How do you perform 1 through 300

[@thishuman]

Thank you :)

[@storm_rising]

nrb approves

[@nikhilparakh3251]

Amazing!!!

[@temik26]

Perfect!

[@davlatbekkobiljonov911]

thank you

[@tareqmahmud3902]

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

[@SEE.ME.N0.M0RE]

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]

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.

[@kda_-uh3vj]

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]

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

[@lackyyyy3098]

@@rebornpixelsproduction u should focus on english yeh :)

[@mariobezuidenhoudt6695]

midpoint = (begin_index + end_index)//2

[@pritam1366]

which ide is used in this video

[@shiili7699]

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

[@huzaim.22]

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

[@shaharrefaelshoshany9442]

wowww, super!!

[@rinku4240]

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.

[@armisol00]

TY BRO

[@Adam-gp3ij]

Awesome

[@jingzhuang4168]

Thumbs up!

[@shahzan525]

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

[@abdulrameez151]

Is the code same for visual code for python on windows

[@MegaKash786]

Abdul Rameez yes

[@avalon4352]

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

[@znpkami]

neat!

[@yunkel]

👍

[@storm_rising]

do you play Minecraft?

[@saviaggarwal8135]

not working in pycharm. Help me!!

[@Corrado49]

check the indentations

[@MelanoBeridze-f8i]

btw his eyes

[@rajivgardas2920]

I love you

[@Pmills9]

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

[@stilgarfifrawi7155]

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

[@tarzan8110]

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

[@agsrf6479]

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

[@shrutikanikhar7987]

yes

[@methulidulanima5344]

Thank you !