Remove Duplicates from Sorted List II | Live Coding with Explanation | Leetcode #82

[@AlgorithmsMadeEasy]

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[@mengyuanzhang9288]

This is literally the most vivid explanation I've ever seen. THANK YOU SOOO MUCH!! Finally understood how to remove duplicates from a sorted list. I had struggled for hours.

[@AlgorithmsMadeEasy]

happy to help!! Please like, share and subscribe to the channel.

[@poetryiscodingdecoding7965]

Literally this is the best explanation for this question ...The way she developed the intuation and then coded ..not even found helpful on others channel and even foreigners...

[@AlgorithmsMadeEasy]

Glad you enjoyed it!

[@harinijeyaraman8789]

This video has such a crisp and precise explanation at the beginning. Found this very helpful !

[@AlgorithmsMadeEasy]

Thanks ! Glad tou liked it !! Keep learning.

[@badabeta6973]

this is the best explanation I found so far

[@ashishshahpur7105]

This solution is good for Java as there is automatic garbage collection. In case of C++, it will run perfectly but there will be memory leaks as the memory on the heap will never get cleared. How do we approach this in that case?

[@demohamnead8662]

Free the memory before the program ends?

[@ziyadauti3676]

Best explanation compared to all other videos on this question #82 ....🤗

[@consistentthoughts826]

Very good explanation I was not able to visualise like this Now I am able to solve

[@AlgorithmsMadeEasy]

Thanks @Renuka Glad you liked it !! Keep learning, happy coding !!!

[@nitin4598]

Great visualization with pointers !.. My code was giving errors for some edge cases, then watched your video and it helped me. Thank you

[@AlgorithmsMadeEasy]

Glad you liked it !!

[@shakti051]

Explained so clear and precise

[@aviralkaushik9425]

such a great Explanation,, I did not understand the dummy, or what it's working,, but now I totally understand, thank you so much mam🤗

[@arjunreddynarala]

Great Explanation👌👌, keep doing for more problems.Its a request.

[@lavanya_m01]

Awesome explanation!! Thanks :)

[@AlgorithmsMadeEasy]

Glad you liked it!!

[@aby.t]

great explaination and visual, keep it up!

[@AlgorithmsMadeEasy]

Glad it was helpful!

[@anishsuman1371]

visualization of pointer is very important i like your presentation

[@AlgorithmsMadeEasy]

Thanks @Anish 🙂

[@listentobooks3592]

Great Help 😇thanks

[@AlgorithmsMadeEasy]

Happy to help

[@anujtiwari7218]

great explanation mam,

[@AlgorithmsMadeEasy]

Glad you enjoyed it!

[@sharuk3545]

one of the best Solution

[@AlgorithmsMadeEasy]

Thanks!! 😁

[@cp65143]

Clear and really helpful😇

[@sophia0282]

Thank you sooooo much for the explanation. I had tried to demo the process by myself and got confused.

[@AlgorithmsMadeEasy]

Glad you liked it !!

[@shantanukumar4081]

great explanation

[@AlgorithmsMadeEasy]

Glad it was helpful!

[@asifkhan-jk4po]

Explained it nicely.

[@AlgorithmsMadeEasy]

Thanks @asif !!

[@vedantagarwal22]

Very good explanation . Thankyou !!!

[@AlgorithmsMadeEasy]

Thanks @Vedant 🤗

[@rohandas4172]

Best solution

[@AlgorithmsMadeEasy]

Thank you!!!

[@bellanatrisha1201]

thank you so much

[@AlgorithmsMadeEasy]

You're welcome!

[@RAJ_K_]

well explained!

[@AlgorithmsMadeEasy]

Thanks

[@siddharthdwivedi3263]

Very nice explaination!!

[@AlgorithmsMadeEasy]

Thanks

[@prathameshraut6579]

We have used while inside while loop so time complexity will be O(n2) right? Correct me please if I am wrong...

[@Apoorvpandey]

Clean explaination!

[@adityasrivastava8196]

Awesome Explanation Ma'am !!!!

[@AlgorithmsMadeEasy]

Thank you! 🙂

[@himanshusharma1066]

simply amazing solution:-)

[@AlgorithmsMadeEasy]

Thanks !!

[@binu44464]

nice explanation

[@AlgorithmsMadeEasy]

Thanks !! 😀

[@hydrocy.9165]

2:34 why not prev = head->next?

[@noobff5624]

Bcs if we move prev is equal to head ->next then the value 4 will also come that we do not want and this will update the prev That is why we do prev next is equal to head next so we can change prev next any time

[@ishaankulkarni49]

great video. how do we know when to use a dummy node?

[@khushinaudiyal2786]

I wanna know the same thing!

[@codersgarage2279]

Well explained. thanks

[@AlgorithmsMadeEasy]

Thanks @Sudha. Happy coding !!!

[@sampannapokhrel]

A little confusing. When the head moves from 3 to 4, as said earlier in the video why didn't you move the prev to 4 as well and if you move the prev the algo doesn't work.

[@Idk-qg7hb]

awesome video, thanks

[@kuldeepparmar6782]

mam if you use ListNode dummy = new ListNode(0); does it give same result why we should use ListNode dummy = new ListNode(0, head);

[@yereneager]

if u use first ListNode dummy = new ListNode(0), then in next line you need to also specify dummy.next = head, both are same thing

[@korosensei3780]

how will duplicate->next return only the required nodes ?

[@PankajYadav-kf3dl]

Mam at the end, "prev" pointer will also come to node 5, right?

[@systemforge]

Brilliant

[@pydjango9812]

Thanks

[@bhupeshbhatt4849]

Crisp | करारा

[@AlgorithmsMadeEasy]

👌👌

[@naveenyadav3700]

🥰 great

[@AlgorithmsMadeEasy]

Thanks !!

[@shivendrayadav3991]

Time Complexity you explained is Wrong ... In best case it would be O(n) else it will be O(n)^2.

[@sahilbarua5202]

no it will always be o(n) cause the outer loop does not iterates over the skipped element that inner loop does

[@sssumeet]

great

[@gantakailashnath]

Can anyone tell me why this code is getting runtime error in gfg. Node* removeAllDuplicates(struct Node* head) { //code here Node* dummy=new Node(0); dummy->next=head; Node* prev=dummy; Node* temp=head; Node* nextnode=temp->next; while(nextnode!=NULL) { if(temp->data==nextnode->data) { while(temp->data==nextnode->data && nextnode!=NULL) { nextnode=nextnode->next; } prev->next=nextnode; temp=nextnode; nextnode=nextnode->next; } else { prev=temp; temp=nextnode; nextnode=nextnode->next; } } return dummy->next; }

[@louischou6780]

why do we need to do head = head.next in line 27?

[@manojpatil7351]

If values are not equal we need to move both prev and head so after moving prev we move head

[@SatishKanaujiyaeb]

Edge case this solution will fail when when size =1

[@adityachowdhury20]

How it is O(n)?

[@cricsinghvlogz]

nice

[@AlgorithmsMadeEasy]

Thanks Pawan 👍👍

[@xinniu3145]

When I conver this to python, it does not work, could anyone explain that to me? Thank you! class Solution: def deleteDuplicates(self, head: Optional[ListNode]) -> Optional[ListNode]: dummy = ListNode(0, head) prev = dummy while head: if head.next and head.next.val==head.val: while head.next and head.next.val==head.val: head = head.next prev = head.next else: prev = prev.next head = head.next return dummy.next

[@xinniu3145]

Hi, could anyone explain why dummy will point to the first non-duplicate node in the code? when you run prev.next = head.next, the dummy.next will also point to head.next, right? why this is the case? And why dummy just stop at the first non-duplicate node and won't go to the end of the list when you run prev = prev.next?

[@dillitimalsina6003]

actually you are blurred my brother....yes when prev.next points to head.next dummy.next also points to head.next but if head.val!=head.next.val we shifted our pre=prev.next so only the referernce pre is shifted the actual object isn't been modified .so for that reason dummy sticks to the very first.....Thanks

[@ranbirpalsingh2245]

Can anyone explain how actually the dummy pointer is getting changed?

[@ranbirpalsingh2245]

Eg. If we create temp= head pointer whatever changes we make to temp will not get reflected in head pointer then how the dummy pointer is getting modified?

[@devinpadron5]

@@ranbirpalsingh2245 The "dummy" and "prev" share the same node. So when prev->next is changed, it is also changed for the dummy.

[@kaustavsaha1117]

Does someone copy ur code ? 🤣

[@vaishnavworkprofile5478]

[@rkk1990]

Isn't this a incorrect explanation? We have to just remove the value which is duplicated. Instead you have removed the value itself which is duplicated. Example : 1 -> 2 -> 3 -> 3 -> 4 -> 4 -> 5 ==> 1 -> 2 -> 3 -> 4 -> 5

[@Nk22618]

The question requires only distinct numbers present in original list. So 3 and 4 are not included in the answer

[@plutomessi21]

can we point prev to null

[@vamshibhai5855]

Made it damn Easyy

[@AlgorithmsMadeEasy]

Thanks 👍👍

[@sivasanjayraahulm7947]

Thanks for the clear explanation.

[@AlgorithmsMadeEasy]

Glad you liked it !!

[@yashindane2844]

Thanks