Wow. This should be the #1 search result for quicksort in KZitem. Understood it, and am now going to code it!
@enriquejaimes3368
5 жыл бұрын
Beni D agree, all others are very confusing.
@LeoUfimtsev
6 жыл бұрын
I've watched about 6 videos on Quicksort. This one is really the best because it first explains the theory and then the in-place algorithm, where as most other videos only explain one or the other but algorithm is confusing if you don't understand the theory behind it. Thank you for this post. The reversed on-glass writing is kinda cool as well. Kudos.
@lucasv4q
6 жыл бұрын
agreed!!! holy god this is mind blowin. great work sir!!
@kosiak10851
5 жыл бұрын
Did you really believe that he was writing inverse? And His left-hand writing is just coincidense then? Don't be naive! The video is mirrored obviously!
@Raminder55
3 жыл бұрын
Can you please help me with Sorting a Singly Linked List using Quick Sort. Please whatapp me if you can help me +919041121318 or mail me at mann.ramin@gmail.com. Thanks In advance..
@rosali7551
3 жыл бұрын
exactly!!
@piyushsharma1638
6 жыл бұрын
teaching style is awesome.
@hackpiece3094
4 жыл бұрын
The only Quicksort vid that was Quick to understand ❤️
@markdanskin8202
2 жыл бұрын
I feel like I watched 10 other videos and read a few articles about this but this finally got it through my head properly. This is really something that needs to be explained just like this to understand. I was getting far to bogged down with the recursion element to fully grasp the simplicity of this algorithm. This is a great explanation because it really just boils it down to what is actually happening, and the logic. Rather than getting encumbered by the actual implementation in a particular language.
@abc17034
4 жыл бұрын
Am I the only one who is impressed not only with his algorithmic interpretation, but also with his digital whiteboard
@oo-gr2sw
2 жыл бұрын
I think he uses translucent/noctilucent board markers.
@jiageng1997
6 жыл бұрын
Amazingly done... my own lecturer left me more confused than before when he spoke about it
@imlijunglalongchar1858
5 жыл бұрын
I just spend the first 2 mins trying to figure out how they filmed it XD
@benzeltser9851
4 жыл бұрын
probaly a transparent wall and mirorred video by edit
@manuelfideles9468
4 жыл бұрын
it's called learning glass, it reverses the image in real time. No editing whatsoever
@minar7555
4 жыл бұрын
@@manuelfideles9468 no, the learning glass aka Lightboard does not reverse the image in real time. "...The lecturer writes on the glass surface with fluorescent markers while the session is recorded...Because any written text will be backward in the direct camera view, the text orientation must be flipped, either by pointing the camera toward a mirror reflecting the Lightboard and the presenter or by digitally reversing the image..."
@errorgrisha
3 жыл бұрын
First time I was same )
@nakulankurmullam2982
3 жыл бұрын
Glass wall and video mirroring Edit: spelling
@Revelatus
6 жыл бұрын
swop
@FredoCorleone
5 жыл бұрын
It seems correct even though it sounds weird
@LudwigvanBeethoven2
5 жыл бұрын
Its an optimized version of swap. Performs at least 10 times faster
@abhishekdas2930
4 жыл бұрын
He is British.
@tyrt400z
3 жыл бұрын
I was like "why is he making fun of how he says swap" and then it hit 6:29 and I understood what you were referring to XD
@BigMarini
5 жыл бұрын
I'm Studying here in Sandiego SouthWestern College, Dr. Edwards you inspire me to transfer over SDSU to finish my Computer Science degree
@ponka128
5 жыл бұрын
One of the best explanations of Quick Sort. Thank you !
@guygreenleaf
4 жыл бұрын
These videos have helped me through my data structures courses IMMENSELY.
@FLYAEROBOY
6 жыл бұрын
Wow. Best Quick sort explanation. Deserves more views
@ythien7147
5 жыл бұрын
Thanks Dr.Edward This video is really clear. I had a hard time in class to understand this.
@acemccrae7862
6 жыл бұрын
Thank you, been trying to understand this for 4 videos including my instructor. Good Job.
@ujtelomvan0414
5 жыл бұрын
All the videos are different. Wtf? Now what?
@linlinli2440
2 жыл бұрын
thank you, this is the best quick sort i have seen, thanks.
@pacodinorin4577
3 жыл бұрын
This was the best way to learn it, I'm Mexican and my teacher is so bad, thanks to you teacher Rob
@__kpsingh__
4 жыл бұрын
This should be at the top of the search list.
@sudajared
3 жыл бұрын
Best explanation of quicksort I have found so far
@ramonaichim5150
Жыл бұрын
THE BEST EXPLICATION FOR QUICKSORT!! THANKS
@RicardoBuquet
2 жыл бұрын
This is the best explanation I have seen so far.
@raymonddevries5341
4 жыл бұрын
Best explanation of quick sort I have found! Thank you.
@singsarav
4 жыл бұрын
Excellent method of teaching. Every one can easily understand
@christopherward7232
6 жыл бұрын
This was a great video! Actually managed to follow through your method and stopping to code each step that you explained. Thanks :)
@SageofToads
6 жыл бұрын
Best quicksort video ive seen.
@zheyuanliu4881
3 жыл бұрын
Thank you professor!! This is really clear and understandable, I now understand how partition work and how it works with pivot point.
@seankalbak544
6 жыл бұрын
Well done and nice job with the reverse writing. That made the video really viewer friendly.
@twerkyfingers
3 жыл бұрын
This is the best video on quick sort!
@FredoCorleone
5 жыл бұрын
This guy is awesome, I'm learning sorting algorithms thanks to him. One day baby I'll be sorting integers at Microsoft! _function quickSort(array) {_ _if (array.length
@mandolinic
5 жыл бұрын
In practice, the number of times you ever need to sort a list of pure numbers is small. It's far more common that you need to sort some structured data, where there's some item within the structure that is the sort key. When I started programming 40 years ago, it was reasonably common to hand code a sorting algorithm for some application, now every modern language comes with a Quick sort algorithm that you no longer need to worry about. How it works is of purely academic rather than practical interest.
@MegaRc1989
6 жыл бұрын
how are you writing backwards!?
@yasahanzengin3329
6 жыл бұрын
He's writing on a glass.
@phillippebr
6 жыл бұрын
They are filming a mirror. He is writing normally in a glass (so everything is backward) and they are filming a mirror pointed to it (making it forward again).
@hussainm8407
6 жыл бұрын
or theyre just flipping the video in post
@FlamAble94
5 жыл бұрын
@@hussainm8407 BAHAHA xD
@mahmoudnadi1992
5 жыл бұрын
sorcery
@omarabdelkader5214
8 ай бұрын
Thank u for ur great explanation, got it from the very first time
@akruijff
2 жыл бұрын
8:50 yes, but if the list is sorted, then the middle is better.
@isaacdouglas1119
4 жыл бұрын
3:41 wouldn't you have to quicksort one more time since it's not guaranteed at that point that the remaining list is sorted? The list could still be [12, 11] instead of [12, 14] at that point.
@RickAstley1988
4 жыл бұрын
That's the only problem in quick sorting, but it happens rarely that's why quick sort is being used mostly
@isaacdouglas1119
4 жыл бұрын
Kurt Weyne Gaso don’t think that’s a problem with the algorithm itself they just forget the last iteration
@sinify6676
3 жыл бұрын
@@RickAstley1988 i don't think people use "sorting algorithms" with small chances to just return unsorted data..
@nikomiller6168
3 жыл бұрын
Using the last element as a pivot is necessarily not a good option if there is even a slight chance that the list could be (nearly) sorted. A good option for pivot selection is the median-of-three method in which you choose the median of the first, middle and last element of the list as your pivot. This leads to efficient behaviour for all inputs.
@reynaldoruizflores
3 жыл бұрын
How can we exactly count the number of comparisons? I establish a counter for 10000 number am I obtain 9999. If I consider the recursion -1 each time the numbers goes to 12K. Depending of the start or end or media election differs too.
@jakubfraczek1208
Жыл бұрын
Very good explanation! Thank you very much :D
@majuran
4 жыл бұрын
Best video...... finally understood the concept... thanks sir
@JoffreyB
6 жыл бұрын
but what about array of |8|10|7|12| , out pivot is |12|, i and j counters in this case will go together until the end, coz all elements are smaller than pivot. And in the end we should switch |7| with |12|, isn't it? but we will get then |8|10|12|7| , which is far from true. Somebody explain me please this moment
@noelthomasbejoy3089
6 жыл бұрын
Watch the vid agin .we skip through the i(update it by 1) when element(i)>pivot.so swaps take place before pivot and element(j )swap.
@mrmrigank7154
5 жыл бұрын
Actually in that case counter who is remembering current posn will remain at 8 and other counter which is finding 1st element greater than 12 will iterate and end the array nothing will happen. And in next step you will send arr 8 10 7 in recursion and 12 in recursion
@911wildman911
5 жыл бұрын
I believe I've found an answer here, having encountered the same confusion when reviewing this myself. When you have this scenario, you simply do not perform a swap at the end. The final value before the pivot value is considered to be in its "sorted" position. From there you can mark the final value sorted and continue the process with a new pivot.
@bzavolovich
2 жыл бұрын
Thank you for this wonderful explanation!
@sandyjust
3 жыл бұрын
So the swapping of 6 and 8 is not required. Just use the last element in the list. I think this is the inplace quick sort using Lomuto partition schema.
@johnyhawkahsan
6 жыл бұрын
Awesome! Very short and to the point.
@KA-jb4qv
3 жыл бұрын
how come the video was captured?.. he seemed writing in air, and he is facing opposite to us
@slippinchillin
2 жыл бұрын
I would give 10 likes if I can for this video! Very well explained! Thank you!
@sanjeevkumarsen4838
3 жыл бұрын
Superb explanation 🙏🙏
@travel_with_dimpi
5 жыл бұрын
Great explaination and u r sophisticated person
@MuntahaZad
4 жыл бұрын
Thanks a lot! Also for no annoying music!
@connorjones6896
6 жыл бұрын
Thankyou! you made this concept easy to grasp
@JoffreyB
6 жыл бұрын
i can't get, what is the second part about?
@nishanthkr2838
3 жыл бұрын
What sorcery is this
@foodandmoney
5 жыл бұрын
Excellent explanation.
@xiaofan9102
3 жыл бұрын
beautiful explanation!
@vishal24000
3 жыл бұрын
'crystal' clear.
@8971felix
5 жыл бұрын
Excellent explanation
@ruicsf
3 жыл бұрын
Thank you!
@number1neek
3 жыл бұрын
The comments here: 🤯 I was much more amazed by how he was able to disappear and then reappear in almost the same place! Then I realised, this must be what recursion is... I am learning!
@MasonAulsbrook
Жыл бұрын
Seems a lot easier to just do a normal sort smallest to largest. Don't understand the reason for the complexity.
@knightyang1561
6 жыл бұрын
I still don't understand why choose the middle number as pivot point and then swap it with the end number in the almost sort list? Am I miss something?
@icosmini
5 жыл бұрын
That is confusing, he shouldn't have said that. You actually simply choose the last number as pivot. And you do that so that you can freely move all the other numbers around. And then at the very end, when you have the set of small numbers and the set of large numbers, you put the pivot between the two sets.
@mrmrigank7154
5 жыл бұрын
@@icosmini it is not confusing actually you can chose any number as a pivot, then have to swap it with the last one ,, choosing last one as a pivot is convenient . pivot means here that you have to place this element at its right place and left elements must be smaller and right must be bigger
@mrmrigank7154
5 жыл бұрын
right place means where it should be .
@ahmidahmid9303
5 жыл бұрын
that will help alot if you sorting nearly sorted set where there will be less swaps mostly if you use the mid number
@huynhat50
5 жыл бұрын
middle is for the meaning, the last is for the implementation
@911wildman911
5 жыл бұрын
Something does not appear to be correct here or maybe I am misunderstanding. With the 8, 10, 7, 12 sort you would do if you had continued this example, all the elements are less than the pivot (12). Your blue/orange counters would stay together until the end, resulting in a swap of 7 and 12, resulting in 8, 10, 12, 7. This is not correct. Is there some gotcha or small detail here that I am missing in which the result would come out correct? Thanks!
@bobhutchinson3638
4 жыл бұрын
>resulting in a swap of 7 and 12 You would end up with swapping (12 with 12) nothing BUT! You would have a new pivot winch is 3(12). End the next iteration would be: leftSort(0, 3 - 1), rightSort(3 + 1, 3)
@short_cut_hub
4 жыл бұрын
Thank you sir Great work😊
@ИльяЛагойда
6 жыл бұрын
Very good lessons. Thank you!!!
@bobhutchinson3638
4 жыл бұрын
The partitioning algorithm is not optimal. If an array is in descending order the swap would do unnecessary job.
@chigoziea.991
5 жыл бұрын
I do have to say this algorithm is just slightly different than some other youtube videos :P. Great video!
@chandramohannegi
6 жыл бұрын
best quick sort thanks
@sathwikchintalapudi1243
4 жыл бұрын
Nice video thanks
@YiANgO5
4 жыл бұрын
Best explanation
@hujake5406
4 жыл бұрын
THANK YOU SIR
@abdellatifsraiti2032
4 жыл бұрын
THANK YOU
@Sgoose105
4 жыл бұрын
The sound made between the pen and the glass...
@fireflies15
5 жыл бұрын
good one. thanks a lot
@Maen963
4 жыл бұрын
BEST OF THE BEST !
@tirupatirao7521
4 жыл бұрын
Darkmode teaching 👌👌😉
@x9466x
4 жыл бұрын
*s w o p*
@va9if
2 жыл бұрын
dat breathing
@ianpoulsen5623
3 жыл бұрын
am i going crazy or did he just say 10 is less than 7
@amphivalo
7 жыл бұрын
Thanks
@xoxoo4877
6 жыл бұрын
Great
@sty1623
7 ай бұрын
Its called quick sort but its not the quickest
@kosmickarma29
6 жыл бұрын
How the hell you write in mirror image!!??@#£_
@swolebastard531
6 жыл бұрын
Either the guy is brilliant or they mirrored the video afterwards...
@kosmickarma29
6 жыл бұрын
Yeah....actually I searched about this on the internet...there is something called lightroom...They do mirror the video afterwords....
@theanonymoustalk
5 жыл бұрын
"swop"
@zbynekjuros5139
5 жыл бұрын
Unacceptable 4:10 !!
@ramiz6260
5 жыл бұрын
+
@nandkishorenangre8244
6 жыл бұрын
Men in BLACK for a purpose
@miwe-zl3io
Жыл бұрын
אופס נפל הפקק 04:10
@ננה-ק5ע
Жыл бұрын
😆מי את ילדה מוזרה שקוראת לעצמה MIWE?????????? אני רואה שהלכת בדרכי
@miwe-zl3io
Жыл бұрын
@@ננה-ק5ע חחח מה אני אעשה אף אחד לא שם לב🫣
@ננה-ק5ע
Жыл бұрын
@@miwe-zl3io עוד רגע את מוצאת לך פה חבר. תזהרי😁
@redscorpions7440
5 жыл бұрын
too fast , not explaining properly
@tsukikage
4 жыл бұрын
This guy is creepily good at writing backwards...
@jrhager84
3 жыл бұрын
I hope you're kidding. lol
@tsukikage
3 жыл бұрын
@@jrhager84 No? Am I missing something?
@tsukikage
3 жыл бұрын
Oh, did they just mirror the video?
@jrhager84
3 жыл бұрын
@@tsukikage bingo
@Nikki-vg2pu
6 жыл бұрын
Best explanation I've found so far!
@cornevantonder7439
6 жыл бұрын
I have been through video after video, website after website and NONE of them were able to help me understand quicksort. Within the first 2 minutes of this video it all made sense. THANK YOU!!!
@krisshore2917
5 жыл бұрын
I finally understood after watching this and was able to implement the algorithm. Thank You!
@tannerbarcelos6880
3 жыл бұрын
Clear. Concise. To the point. Will take a few watches but it was so clear and made so much more sense than what was taught in my algorithms class at school , lol.
@norvusordoseclorum
Жыл бұрын
You can tell dropping that lid really bugged him
@ibtisam.6309
5 жыл бұрын
You're brilliant! Best explanation so far.
@Farrukhw
6 жыл бұрын
Thanks a lot Rob for all your hard work and making it easy to understand... Really appreciated ... :)
@appleseedan
4 жыл бұрын
swop
@jayaprakash1951
2 жыл бұрын
Bro you are the best ! Man literally watched 7 videos to understand this method but your video is the one to understand this method
@ArjunPatel-hi5eq
5 жыл бұрын
LOL WOW IS HE WRITING BACKWARDS?
@akshaysapkale2789
6 жыл бұрын
Dyslexia 🤔🙍 But anyway it was fun and very helpful for me
@Jagadishkumar4646
4 жыл бұрын
First value is taken j last value is pivot is taken if first value j is less then pivot what we do and i is taking increment to the j
@jidejaydee
3 жыл бұрын
am too lazy in writing a comment but this tutorial made me do that! THANKSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS
@halcyonramirez6469
4 жыл бұрын
I don't understand 5:18. what if it wasn't a 10 but a 1? where would you swap that to?
@madhatshahda4179
Жыл бұрын
really great work . It felt like listening to the John Danaher of sorting xD
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