L2. Deletion and Insertion in LL | 8 Problems

[@samxd4296]

0:00 Intro 0:34 Deletion of the head of LL 6:18 Deletion of the tail of LL 15:47 Deletion of the Kth element of LL 30:14 Delete the element with value X 32:15 Insertion at the head of LL 35:15 Insertion at the tail of LL 38:41 Insertion at the Kth position 51:22 Insertion before the value X Thank You Striver for the Playlist and your hard work

[@GotetiKrishnasrikar]

[@immortal6978]

A hell lot of hardweork for the community. Hat's off your dedication to coding. Hit like on video if Agreed.

[@AnshGupta-pr7qo]

How could someone be so perfect at explaining.....literally hats off to you striver If in life i ever had a chance to meet or see you it'll be one of mt best day

[@loremvampire6343]

I was waiting for this playlist since one month. Thank you so much Sir

[@chrish4403]

So grateful , Linked list is a topic ive been avoiding to learn from my boards due to lack of understanding, but in just two videos you have made me so well versed with linked list, wish i found this video two years ago,

[@vedikamishra009]

same, but 2 years ago it didn't exist sadly :(

[@publicuses8589]

Striver bhaiya u r a gemmmmm lot's of respect for u 🫡🫡

[@ronakvaghela2714]

One of the best coding content on the whole youtube. You're an inspiration to everyone and a great example of how hardwork looks like. Thanyou so much for doing this. you deserve everything you wish for and hope to see such content more from you.

[@5640_GlenaSAHA]

you are the best one to teach linked list in the easiest manner, I wasted my whole third semester understanding linked list but still failed. But you are really amazing!!!!

[@ShubhraneelChakraborty-cj8zm]

For insertion of a node at the head of the linked list, we can also do this: Node temp=head; head=val; head.next=temp; return head; What its doing is that, the previous head is being assigned to a temporary pointer, and the new node being inserted (val) is being assigned to the initial head pointer (head), a simple swap. Then the head's next is being assigned the temporary pointer (holding the initial head) to link the new head and the previous one. Hope that helps. And thank you Raj bhaiya for such an amazing video again, the explanation was so clear.

[@GirishaMalani-fs4ch]

but then what will be temp->next?

[@ShubhraneelChakraborty-cj8zm]

@@GirishaMalani-fs4ch Forgot to mention, it is in Java, so it will be collected by the garbage collector. For C++, you need to free that pointer.

[@VishalGupta-xw2rp]

Notes 33:33 Insert at head 50:01 Delete Nicely done

[@Ranganadhamkrishnachaitanya27]

How code will work I'm confused

[@anuragprasad6116]

For deletion at k index, you can check if(cnt == k-1) and perform curr->next = curr->next->next; instead of keeping a previous pointer.

[@purvamjain4953]

it wil give u error, assume u have 4 elements and they asked to remove 5th element. with cnt=k-1 it will try to access next element of null which will throw error unless u catch it manually

[@sanjayutchula7849]

In order to avoid this we can maintain a int size variable in class and declare it public update every time we add or delete node and for deleting a kth node we can check at starting if it exceeds the boundaries and throw an error else we can run a for loop for k times and move the temp pointer to reach before which we want to delete ​@@purvamjain4953

[@VivekKumar-kx2zf]

@@purvamjain4953 no that can also be skipped using a if condition.. Look at this code : static Node DeleteAny(Node head, int k) { Node temp = head; if(k == 1) { head = head.next; return head; } for(int i = 1; temp != null;i++) { if(i == k-1 && temp.next!=null) { temp.next = temp.next.next; } temp = temp.next; } return head; }

[@mdfaizanmdfaizan6041]

​@@purvamjain4953we can apply for a condition before

[@santhoshl-zq1op]

But , at the starting itself , we check the condition if( k > lengthof LL ) return head;

[@AmanSharma-xy1qm]

All the video lectures and the articles helped me a lot to gain confidence in DSA and will be helping me in the interviews. Thank you Striver bhaiya for bringing such amazing content for free.

[@hareshnayak7302]

Understood,Thanks striver for this amazing video.

[@prathameshjadhav2942]

Next level teaching ❤

[@utkarshsingh09]

His teaching skills!!! Hats off!

[@5640_GlenaSAHA]

believe me on this when i say he is the best!!

[@vaishnavi.pvaishnavi.p8474]

superb explanation sir...... i want to listen you more and more

[@dipingrover1970]

Such a hard topic explained in best way possible Thanks a lot man 😊.

[@S3aw0lf]

Superb explanation, was able to do the code by myself starting from 2nd video after understanding you explanations.

[@prajjwalsinghrathore9458]

Thanks bhayya for the playlist, we appreciate it , it would be good if you add time-stamp to it.

[@Rohit-ht8kd]

at 29th min the code for if(k == 1) is head = head.next; return head: but you have written Node temp = head: return head;

[@prathamrajsrivastava9807]

hey striver... when's the strings playlist coming out??

[@uchihaitachi5376]

Striver love you bro how can you make things very simple thank s bro❤

[@pranaycc]

Crisp And Detailed, 💕💕

[@chetna253]

a lot of hardwork ...respect bruh

[@GauravGupta-no7sf]

00:04 Deletion and insertion in linked lists 02:21 Freeing memory in C++ and Java 06:58 To delete the last element in a linked list, the list must have at least two elements. 09:34 Deleting the tail element from a linked list 14:28 Demonstration of removing elements from a linked list in Java. 16:46 Deleting elements from a linked list 21:04 Discussing traversal and conditions for stopping 23:27 Managing deletion and insertion in a linked list 28:03 Removing elements from a linked list in Java 30:23 Deleting elements from a linked list based on given value. 34:35 Inserting before and after the head in linked list 36:44 Inserting a new node at the end of the linked list 41:06 Insertion in linked list at different positions 43:21 Traversing and manipulating temporary in linked list 48:12 Covering all the H cases for node insertion in a linked list 50:27 Inserting and deletion in linked list 54:42 Insertion before a value in a linked list

[@glife54]

Ai

[@lordgaming7178]

Thank you for the explanation

[@AtanuDebnath]

Raj Dada , Love you! ❤❤❤ You make the hard things look so easy!

[@sauravkumar9900]

Bhaiya please make a playlist videos on Strings from basic to advance

[@Ady-tf1jm]

Best Playlist for beginners.

[@harshitgarg2820]

Completed this video and done all the 11 questions of the sheet.✅✅

[@himanshukaushik9223]

Bro last 2 questions ma compilation error bta Raha insertion ma sheet ka

[@harshitgarg2820]

@@himanshukaushik9223 bhai typos me error hogi, ek baar dobara check kro fir run krna, agr vs code use krr rhe ho toh mingw ko reinstall krke dekho

[@himanshukaushik9223]

Bhai coding ninja pa last 2 question compile error bta rahe hai

[@newbie8051]

0:34 ha, my initial thought was to use a slow and fast pointer, and when fast pointer approaches the node to be deleted, we skip it by having next of slow pointer be the next node

[@ompawar9791]

I searched for this kind of videoes from last few days. Now i got that man ->striver.........YOU CREATED ME AS A POINTER WHERE I STORED ADDRESS OF YOUR CHANNEL IN MY HEART❣❣❣❣❣❣❣❣

[@ompawar9791]

wow

[@DeepikaaSelvam]

Waiting for Strings Playlist !.. No one is talking about the String Concept!!!

[@MOHAMMEDMOJAHID-rg8sc]

Me too

[@JalalMujawar]

Code for removing a node without knowing the head: public void deleteNode(ListNode node) { node.val = node.next.val; node.next = node.next.next; }

[@AtulPal-i5s]

Waiting for String Playlist

[@HarishKumar-jm5bk]

Striver can u please make series on binary numbers number theory and bit manipulation there is no video on youtube please make this video if possible

[@dhikshitha7694]

Awesome video! In deletion of last/tail node in the base case if either the length is 0 or 1 we return null, but when length is 1 we should free the allocated memory that is delete head and then return nullptr right?

[@MyAnish22]

@25:40 timestamp - we can also write prev->next = temp-> next? Also, if k==4 then tail gets deleted but what about indicating prev as the new Tail? Can understand, if any node pointing to nullptr is a tail then its fine.

[@Shikaslad-s5f]

don't know what might be the issue but if k = n+1 where n = length of LL it is still removing the last element from LL Here is the code Node* removek(Node* head, int k){ if(head == NULL)return head; if(k==1){ Node* temp = head; head = head->next; delete temp; return head; } int count = 0; Node* prev = NULL; Node* temp = head; while(temp != NULL){ count++; if(count == k){ prev->next = prev->next->next; delete temp; break; } prev = temp; temp = temp->next; } return head; }

[@omkarsawant9267]

Guys during Insertion kindly modify your node constructor or else you will get argument error. Modified code below-> class Node { public: int data; Node *next; public: Node(int data1, Node* nextNode = nullptr) { data = data1; next = nextNode; // argument added } }; Below Insert Node code--> Node* insertHead(Node* head, int val){ Node* temp = new Node(val, head); return temp; } int main() { vector arr = {2, 5, 8, 7}; Node *head = convertArr2LL(arr); head = insertHead(head, 18); print(head); return 0; }

[@ARNAVGUPTA-s1m]

If we create a dummy node before head, we will not have to worry about edge cases. Just remember to return dummy->next.

[@itsksujan]

35:00 don't we have to update the head to point to the new node that is inserted at the head ?

[@sonyshaw9964]

Indeed supreme quality article

[@shivamswarnkar7763]

In the very last code which he has written we have to write while(temp.next.next not equal to null) instead of while temp.next not equal to null. If I am wrong, would be grateful for corrections.

[@gyanendrasonkar3144]

I feel the condition is fine and safe to have. eg: case1) 1->null key = 1, ele= 2 if (head.val == key) return new Node(ele, head) works. 2->1->null Case 2) 1->2->null key =2, ele=3. temp =head; So , temp points to head, temp @1. (temp,head) 1 ----> 2->null if temp->next->data is same key( 2==2) , yes create a node, x = new Node(ele, temp->next) x 3---> 2---> null ^ | 1(temp,head) temp -> next = x; x 3---> 2---> null ^ | 1(temp,head) 1->3->2->null Another example::: 1-2-3-5-6-null key =5, ele 4 when we found the key, ( temp->next-data== key), stop here and add the node ^^^ head temp 1-----2-----3--------5---------6---null x = new Node(ele, temp->next) h temp x 1----2-----3 4------5----6--null ( remember temp next still pointing to 5 , can't draw ^^) temp -> next = x; h 1-2-3-4-5-6-null I hope it is cleared now...

[@SanthoshaK-px8rq]

public Node DeleteK_ele(Node head, int k){ Node temp = head; if(k == 1){ temp = head.next; return temp; } int i=1; while(i

[@AbhishekRanjan-wk7xp]

but how will you handle the case when k>length of linked list

[@AshokKumar-td2qo]

Hey Striver you are my inspiration. Very thank you for LinkedList playlist ❤❤ Please suggest dbms in english video i can't understand hindi

[@beaware70]

Great explaination sir❤❤❤❤

[@vivekgautam9766]

Make a series on strings from basics to advance.

[@vivekkumar841]

awesomee lecture bhaiya!!!

[@Student-j4u]

to delete kth element when cnt==k can we write prev=temp.next instead of prev=prev.next.next

[@AnujTiwari-g8o]

you are a star bro...🔥🔥🔥🔥🔥🔥

[@doremon81072]

loved it, Jai ho striver bhaiya

[@Ravithasingh089]

Glad to be the First viewer brooooo🎉🎉🎉. Thank you so much for this quality content.!!

[@bullymaguire2335]

is there a python playlist for linkedlist im unable to find it .

[@Ayeshasingh720]

so.... finally i m understanding LL🙂

[@rohitkuttum3102]

in delete tail remeber to free the head if (head->next==null) while using c++ . ignore java,python,js developers.

[@ThakurIsGeek]

good work i have learn alot from you

[@alokkulkarni7854]

when i tried to run the the code in vs code it showed error in many lines especially those where node was used as data type for function , can anyone clear why so ?

[@saitejanedunoori5451]

great work and thank you THALA

[@adebisisheriff159]

Thanks so much Striver!!!!

[@junaidmetkari6365]

waiting for string playlist🙂🙂

[@khushisaraswat5826]

Nice tutorials u have removed the need of such paid dsa courses....

[@jainkokila2335]

55:30 found is bool it cannot store 1 it can store true to solve our purpose

[@HitanshuRathi-zz5vn]

Understood Thanks brother

[@SurajKumar-ku1lg]

why we take for cnt =1 as increase by 1 and why not intialise prev as head as move on

[@Dibyadipan]

I have a small doubt in 3:48 where we are writing the code for removing the head of the linked list. the code snippet is as follows: private static Node removeHead(Node head) { if (head == null) { return head; } head = head.next; return head; } Here if we look at the first edge case where head==null is being tested. If i am not wrong that means the linked list is empty. so if the linked list is itself empty/having null value then it is obvious that removing the head will result in returning the null value right? And Striver said while explaining that if there is only one element too then the element behaves as both the head and the tail so removing the head will result in returning a null value...but here we are not checking that ie we are not checking if (head.next == null ) why is that so could anyone please explain me?

[@SpeedBirb]

because if head->next is null, we are setting head=head->next after the if statement, which will make head=NULL, and return null. So there is no need to check for head->next

[@mma-dost]

The question which was deleting the node whose pointer is given to you not the linked list head pointer that question is not covered right ? Its in the sheet last question Singly LL

[@albela7434]

greatttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttt lecture i ever watched

[@ShubhamKumar-me7py]

hey can we do dsa together

[@agnivadutta969]

In Java, removing head program, isn't the temp variable needs to be set null before garbage collection?

[@TS-oj3vd]

25:31 what if k=2? code will break giving error. prev is still null.

[@shivanisahu8075]

in java how to print full ll with changes when we return head so they print vlue of head only plz tell me how to print new ll

[@pavanisri0512]

Can you do in python also

[@salihedneer8975]

how many videos will be there

[@NewtonVarma]

Hey @takeUforward striver please upload string lectures,

[@himanshukaushik9223]

Anyone submitted last 2 questions on coding ninja it show compilation error

[@hardikpatel352]

Thanks a lot striver, understood

[@vilen2685]

Thankuhh sir for giving code in java !!!!

[@simranmaity7252]

Can you please provide the code ..

[@siyonabansal6703]

why dont we take k-1 instead of previous in kth element

[@algorithm_based]

in some case if the head is not given what we can do ?

[@amanasrani6405]

Thank You so muchhhhh ❤❤❤❤❤🙏🏻, understood

[@Vishu2-3]

27:54 prev -> next = temp -> next; free(temp); correct or not?

[@BadalJena-oh6qu]

inserting at kth positition 38:00

[@ShivamKumar-oj7ud]

in deletion of value...it will not be able to delete multiple values of list

[@satyamrath6818]

Can you please attach the test link as well for practice. Thanks

[@jevinkardani]

can someone explain what is the difference b/w NULL and nullptr ?

[@bharanitharan.m1158]

Hey, When you want to delete 1st position of linkedlist in at any position you got wrong answer

[@purvshah4260]

god level explaination

[@36nchiranjeevi53]

Great explanation

[@DevashishJose]

Thank you so much.Understood

[@darshilmodi6851]

When is the string playlist releasing ?

[@AniketKumar-hf2bo]

thnx for amazing video ❤❤❤👌👌👍👍👍👍

[@radha7492]

sir while deleting the Element using its value like given example mein jab hum 12,5,8,7 mein se 12 ko remove krenge using removesEl(head,12) toh error aa rha h (bhot sari random values dikha rha h), I need help, i checked my code more than 8 times but error nhi resolve ho rha, plss help someone

[@anuragprasad6116]

code to post kr de behn

[@TON-108]

Understood, Thanks!

[@ishita8305]

please upload the strings playlist sir..

[@deepakbhatt555]

nicely explained !

[@anshukumari6226]

Thanks for the video!

[@supernova4467]

idk no why i cant do problem solving i can understand dsa topics pretty easily but cp feels very hard to me like this year codevita questions like orchard , vip cafe , maze runner i could not figure out them im really ashamed of myself

[@VishalGupta-xw2rp]

You start with A20J Ladder

[@NazeerBashaShaik]

Understood, thank you