First I thought this explanation was going bad because the quality of the picture you put is low. But that's actually one of best explanations I've seen, thank you.
Excellent video ... Best way to learn is to sit patiently, watch and practice the mind along with the video (pausing video at various points to do self analysis)..... Reply ·
Great! This was a really clear review. Except for case 3 you only talked about finding the min of the right subtree. One can also replace the target node with the max of the left subtree. Either method works in keeping the tree in order.
Very succinct and to the point. Good video! I loved also the style for representing the different cases so I can rebuild the algorithm my own head without need to memorize anything else.
But what happens to nodes labeled 34 and 36 when we remove their father( when we replaced 30 by 32) Now 34 and 36 should be placed on the left subtree of 40 and not on its right, how to deal with it algorithmically?
When we replaced 30 with 32 we had to have deleted 32 so it is only in the tree once! To see what happens to 34 and 36 in that case, you can watch the video at 2 minutes and 50 seconds (th-cam.com/video/wcIRPqTR3Kc/w-d-xo.htmlm50s) where I had shown 32 being removed. Node 34 would be the new left child of node 40 (and node 40 would be the parent of node 34). Does that make sense?
if I implement the remove method recursively, how can I remove a leaf ? Since by the time the recursion gets to the leaf, we lose access to the parent node
To all future students: There are two ways to do this. You either select the maximum value from left side, or the minimum value from right side. Colleen selects 75 here, but most visualizers will select 65 since it's the maximum from left side. Hence my confusion above
If we start with the tree at the very beginning of the video and delete 32, then we're deleting a node that has only one child. That's a simpler case (than if it had two children) and we can just make 40's left child be 34, which effectively removes 32. We just keep the same connection between 34 and 36, because in general we try to avoid restructuring binary search trees. Does that help?
colleen lewis yes. so while deleting 30 why do u choose to swap 32 in place of 30? we can choose 20. that can work too? while deleting 70 we can replace by 65. which is next smaller that too maintain tree property.? does it always have to be next bigger element?
That's just a convention for what you do when you delete a node with two children. I have chosen to use the next biggest rather than the next smallest, but either would work just fine. Does that make sense?
Two answers: Usually we'd just implement either the next biggest or the next smallest. Not both. We never have duplicate keys in our BST - so that never comes up. If we try to add a key that is already in the BST, we would just replace the old value associated with that key.
this is probably the best tutorial on TH-cam
First I thought this explanation was going bad because the quality of the picture you put is low. But that's actually one of best explanations I've seen, thank you.
This is the best explanation of BST methods I've seen
Thanks! :-)
video from 2013 helping me 6 years later.... thanks!
Glad to hear it! :-) - Colleen
And here for me 11 years later. I hope you achieved your goal from back then!
Of all videos on TH-cam, you posted the best tutorial on BST
Thank you! I'm glad it was helpful to you!
Awesome! clear and concise explaination! İ came here from the Odin project
Glad it was helpful!
What my professor couldn't make clear lecture after lecture after lecture, nor could my TA, you did in 6 minutes. Thank you so much for sharing this.
best explaination , simple language and covering all the cases . THANKS A LOT
Glad it was helpful! Thanks for the note!
This is the best explanation I ever came across. short and up to the point. Thank you.
Thanks Vishnu!
concise and clear, such a beautiful presentation ma'am
Damn ! Tree operations are so easy ! This 6 min video taught me what I couldn't learn in 3 hour class. U r amazing ...thx ...muaahhh :)
This was one of the best explanations I have seen yet, so simple, so concise. Thank you, Colleen
I have checked many insertion and deletion videos, but yours is best one. Sweet, short ,simple and effective though. Thanks.
Small and concise. To the point. Loved it. Thanks alot.
thank you so much for that simple explanation!. i was so confused about this all the time
I'm glad it is helpful to you!
The best video ever.. Made the deletion look so much easier.. I wish you were my teacher
The way you explained is brilliant!!! It's marvellous that you manage the whole thing within 6 minutes. Job well done!!!
amazing explanation. I used to always get stuck in the removal of a node, but now everything is clear.
Learning for my exams at the moment so thank you very much for this video!
TheXHypex Thanks! I hope the exams went well!
It took you 6minutes to explain something our teacher failed to do in 2 hours, thx
Binary Search Tree Delete: 1:45
Excellent video ... Best way to learn is to sit patiently, watch and practice the mind along with the video (pausing video at various points to do self analysis).....
Reply ·
i have my exam in 1 hour, and was getting confused in delete and insert. U made it look very easy. thanks a lot . #awesome
+Abhijeet Joshi Good luck! :) Thanks for the comment!
Algo and Data structures exams in 2 hours. Thanks for saving my life.
Thanks for the note - I'm happy it was helpful! - Colleen
This clears up everything I only 6 minutes!
I'm glad the video is helpful to you! - Colleen
Great! This was a really clear review. Except for case 3 you only talked about finding the min of the right subtree. One can also replace the target node with the max of the left subtree. Either method works in keeping the tree in order.
That's correct. And we only need to replace it with one of those - and we should be consistent about which one we choose.
👍🏿
nice
Using your video to prepare for an interview. Thanks for your help.
Finally. English. thank you so much!!!
I can't believe I understand this now better than after a 2 hours class at the uni
Glad to hear it was helpful!
Thank you so much your explanation is very good and easy to understand....hope you will be uploading such types of explanation in next topics
Very succinct and to the point. Good video! I loved also the style for representing the different cases so I can rebuild the algorithm my own head without need to memorize anything else.
This video might be old but it was so useful and effective!
Thanks a lot! Wish you all the best!
best explination i could find on the subject, thank you a lot
your video is best than other countries TH-camr video
Best explaination
Useful and clear, thanks. BSTs seem like a very useful invention.
professor dude from my uni took 2 hrs to explain this 6 mins and this female wibba explains a whole lot better, thanks a lot madam.
Thank you so much for this video!
Amazing explanation, thank you
i never thought it was this easy
thanks, that was a simple, but very clear explanation.
Greetings from odin!
this helps me. I understand BSTs really well, but removing nodes continues to stump me. thank you for the clarification.
Thank you so much for making such an awesome video that explains the whole idea clearly. It helps me a lot
I'm glad it was helpful! Thanks for the comment!
Very clear tutoriial and nice voice too thanks sweety!
short and effective !!
BomBamBum Thanks! And thanks for the ascii art below! :-)
its 2024 and this's still a great explanation
Thanks so much! :)
THANKYOU SO MUCH😭💓
Thanks for the comment! I'm glad it was helpful! :-)
Very helpful, thank you! I also liked the way you explained it.
Awesome thanks understood it within a time span of 6 mins :D
thank you so freaking much!
I'm glad it is helpful to you!
Fastest and best video -)
This video is really helpful and effective to learn about trees.I am from Bangladesh.Thanks Colleen Lewis ♥
Thanks for the note :-)
Thank you so much! This is very clear and easy to follow!
Pretty concise and clear. Thanks!
Extremely useful! Thanks for uploading.
Thanks! :-) I'm glad it is helpful!
what a badass teacher
Clearly explained. Thanks!
But what happens to nodes labeled 34 and 36 when we remove their father( when we replaced 30 by 32) Now 34 and 36 should be placed on the left subtree of 40 and not on its right, how to deal with it algorithmically?
When we replaced 30 with 32 we had to have deleted 32 so it is only in the tree once! To see what happens to 34 and 36 in that case, you can watch the video at 2 minutes and 50 seconds (th-cam.com/video/wcIRPqTR3Kc/w-d-xo.htmlm50s) where I had shown 32 being removed. Node 34 would be the new left child of node 40 (and node 40 would be the parent of node 34). Does that make sense?
Yeah! Now I see it clearly! Thanks
Thank you soooooo muuuuuuch.
I'm glad this was helpful for you!
colleen lewis you have no idea. I passed my course because of your video. I cant even thank you enough.
Thanks Colleen..
So so much
Awesome simple video!
Super good explanation
What an awesome explanation! Thank you a lot :)
Amazing explanation thank you!
Very Very Very effective thank you so much
Brilliant video, thanks!
awesome..it helped a lot...lucid explanation
This was really good, thank you!
Good explaination. Thanks!
Thanks a lot for your help.
awesome explanation
Thanks! :-)
Amazing video! Thank you
Thanks :-)
short and accurate thanks alot
thanks.. the best.. helped me alot..
Nicely explained!!!.... subscribed... :)
Herrroooo from The Odin Project
This helped a lot thank you. I did something wholly different than this.
Thanks for the video!
Thanks...this was very helpful
very clear. thanks a lot
ma'am you are just perfect :*
Holy shit that was perfectly explained. Thank you.
Thank you! :-)
Thank you for your video.
if I implement the remove method recursively, how can I remove a leaf ? Since by the time the recursion gets to the leaf, we lose access to the parent node
Thank you very much.
i just love this
Thanks! :-)
Good Explanation! Thanx!
awesome video !
thanks!
Nice explanation :) like it ..
thank you very much mam ...
Tried to plot these numbers into a visualizer, and on deletion it selected 65 instead of 75. OP is this a self-balancing tree? WTF?
To all future students:
There are two ways to do this. You either select the maximum value from left side, or the minimum value from right side.
Colleen selects 75 here, but most visualizers will select 65 since it's the maximum from left side.
Hence my confusion above
it helped thanx alot
Thank you!! You're amazing:)
Thanks for the note Hanna!
Helpfull ... thnks
Thank you professor! You helped me a lot! \o/
what happens after deleting 32?
what happens to 34 and 36?
If we start with the tree at the very beginning of the video and delete 32, then we're deleting a node that has only one child. That's a simpler case (than if it had two children) and we can just make 40's left child be 34, which effectively removes 32. We just keep the same connection between 34 and 36, because in general we try to avoid restructuring binary search trees. Does that help?
colleen lewis yes. so while deleting 30 why do u choose to swap 32 in place of 30?
we can choose 20. that can work too?
while deleting 70 we can replace by 65. which is next smaller that too maintain tree property.? does it always have to be next bigger element?
That's just a convention for what you do when you delete a node with two children. I have chosen to use the next biggest rather than the next smallest, but either would work just fine. Does that make sense?
colleen lewis yes. now the main question is how to decide which one choose to swap so that least cost is inccured.
does it also work for equal keys?
Two answers:
Usually we'd just implement either the next biggest or the next smallest. Not both.
We never have duplicate keys in our BST - so that never comes up. If we try to add a key that is already in the BST, we would just replace the old value associated with that key.
thanks a lot
thank you from italy :)
Is there a similar explanation on red black trees insertion and deletion.....help much appreciated :)