Add Two Numbers (LeetCode 2) | Full solution with diagrams | EASIEST EVER

Add Two Numbers (LeetCode 2) | Full solution with diagrams | EASIEST EVER | Study Algorithms

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Күн бұрын

To see more videos like this, you can buy me a coffee: www.buymeacoffee.com/studyalg...
Actual Problem: leetcode.com/problems/add-two...
Chapters:
00:00 - Intro
00:56 - Problem Statement and Description
03:50 - Edge cases and things to be careful about
06:01 - Defining a Solution
08:26 - Dry-run of Code
12:08 - Final Thoughts
📚 Links to topics I talk about in the video:
Linked Lists: • Linked List Data Struc...
Traversing Linked Lists: • Traversing a Linked Li...
📘 A text based explanation is available at: studyalgorithms.com
Code on Github: github.com/nikoo28/java-solut...
Test-cases on Github: github.com/nikoo28/java-solut...
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Пікірлер: 114

@sharpblades117 Жыл бұрын

Just want to say, thank you for covering this in the clean format that you did, this made the video engaging. Keep up these amazing videos.

@johncho9160 6 ай бұрын

i really enjoy your leetcode explanations with the dry run of the code. as somone prepping for interviews, youve helped me a lot. thankyou!!!

@juli13585 6 ай бұрын

Really easy to understand explanation and the best I have seen for this problem, thank you so much!

@JigCode 10 ай бұрын

This is the best and clearest explanation of a leetcode problem that I have ever seen !!!

@naibgulam2336 Жыл бұрын

Really enjoyed this video! Been following your channel to learn how to solve leetcode questions and your videos and organization are super useful and well thought out. Keep it up!

@nikoo28 Жыл бұрын

You're very welcome!

@anujgupta1484 7 ай бұрын

you are truly a gem for DSA learners .

@safar19899 Жыл бұрын

Your solution made the most sense to me. Thanks!

@PremkumarIT 3 ай бұрын

very clear explanation brother ..I so great to find your videos

@Bot__gam_ing Жыл бұрын

bruh you are awesome not even get bored while watching thanks

@cookiebrown3405 5 ай бұрын

this was a beautiful explanation. Thank you

@lil_paha 9 ай бұрын

Thank you ! You make best explanations :)

@adityashinde7815 10 ай бұрын

Thank you brother your explanation is amazing . i understood this problem very clearly

@TheA1facts Ай бұрын

Good work, Keep it up!

@ToireasaMoley-mk3tw 7 ай бұрын

great explanation! so easy to follow :)

@EaseyourLifeBro 2 ай бұрын

You deserve many more subscribers 😃Concise and accurate explanation. No confusion, every point makes sense. Please keep up the good work. 👍

@nikoo28 2 ай бұрын

Trying hard 😇

@KRajesh-ej7dy Жыл бұрын

I Felt Happy After Listening This Thank You Bro

@shubhanshusharma7457 Жыл бұрын

nice explanation, got understood the solution in one video of yours,despite searching others

@nikoo28 Жыл бұрын

glad you found it helpful

@rajeevkumarshetty4911 9 ай бұрын

super broo this is one of the best and easy solution i have ever seen thank you so much for this solution its really helpful🤩🤩😍😍👏👏

@mohammedirfanu8180 10 ай бұрын

You are really teaching amazing sir, I can undestand very clearly❤

@alexpa24 Жыл бұрын

Very well explained. Thanks

@sachinpawar2665 Жыл бұрын

Your leet code solutions are above the par and the explaination is the deadly combination

@nikoo28 Жыл бұрын

So happy to hear that :)

@joaoguilherme-or1ud 2 ай бұрын

Muito Obrigado por essa Explicação fantastica !!!

@nandanupadhyaya4192 7 ай бұрын

Beautiful explanation..🔥🔥

@jean-paulboga8189 7 ай бұрын

thanks for the great explanation.

@PrashantKumar-fk8le 11 ай бұрын

This man explains Best of best on youtube,Huge Salute 👑👑👑👑

@nikoo28 10 ай бұрын

so glad you feel this way.

@sachinpawar2665 Жыл бұрын

Amazing content bro keep going, only time is your enemy, just wait for some time and you will reach to new heights.

@nikoo28 Жыл бұрын

Hope so

@naveenkumarkota2090 4 ай бұрын

understood thanks !

@chakravarthybatna1589 10 ай бұрын

awesome explanation bro

@jmajid774 Ай бұрын

Thanks. very cool video

@itkavyas.p6176 8 ай бұрын

i just started DSA as beginner after watching most of the solution your solution is very simple and easy please post more videos and support peoples ..... you earned the new subscriber

@nikoo28 7 ай бұрын

thanks for the sub 😄

@preetomadityapranoy429 Жыл бұрын

Thanks a lot for this simple and easy solution. I solved the problem but test case 1565 out of 1568 was my stuck point and after that, I found your video. Keep up the excellent work.

@nikoo28 Жыл бұрын

Well done

@gamersrock392 11 ай бұрын

i really appreciate you sharing solution and telling how converting linked list into integers then adding and then again converting into linked list method is inefficient as thats what came in my mind while first solving solution

@nikoo28 10 ай бұрын

glad you found it helpful

@Anuli-Edom 9 ай бұрын

Best explanation to this i have seen so far

@nikoo28 8 ай бұрын

yay!!

@No-Nama-_-.0 2 ай бұрын

Thankyou sir 😊😊

@natnaeldesta5932 11 ай бұрын

explained simply! thank you

@nikoo28 11 ай бұрын

Glad it was helpful!

@bashlaev_ka 10 ай бұрын

Частично понимал перевод, но за счет очень классного визуального объяснения понял объясняемый алгоритм. Круто, спасибо, было интересно

@nikoo28 10 ай бұрын

Я так рада, что смогла вам помочь.

@krishankantsaraswat2276 Ай бұрын

00:02 Adding two numbers in linked list format with reversed order 01:39 Adding two reversed numbers represented as linked lists. 03:27 Handle zeros at the beginning of linked lists while adding numbers. 05:06 Carefully consider edge cases for adding large numbers and handling overflow. 06:45 Adding two numbers using pointers and carrying over. 08:23 Code implementation and algorithm explanation 10:02 Splitting out the sum and carry after adding two numbers 11:47 Understanding the time and space complexity of the solution Crafted by Merlin AI.

@satishagrawal5015 10 ай бұрын

nicely explained ,thank you

@nikoo28 10 ай бұрын

Glad it was helpful!

@suneosama939 9 ай бұрын

Thank you

@BCEKaushikKashyap 10 ай бұрын

thanku so much

@winningPages Жыл бұрын

Worth the time

@nikoo28 Жыл бұрын

appreciate your feedback

@bibekanandapattanaik4293 7 ай бұрын

Thanks

@mennahassan5828 Жыл бұрын

thank u so much.your explanation is quite simple

@nikoo28 Жыл бұрын

Happy to help

@mennahassan5828 Жыл бұрын

@@nikoo28 but why not all medium questions in leetcode have videos.i suggest to increase number of medium questions

@nikoo28 Жыл бұрын

@@mennahassan5828 It takes time to create quality content. I take almost a total of 10 hours to create one video with proper thumbnails, companies that it has been asked in, github links, thumbnails, editing etc. etc.. I also try to upload the content in full 4K quality for best viewing experience. Nonetheless, stay tuned...I am constantly trying to cover more and more important questions as time permits :)

@mennahassan5828 Жыл бұрын

@@nikoo28 thank you so much.appreciated

@SinchannDekesuki Ай бұрын

i have a doubt in this question i was able to solve this problem without using any extra space after that i saw many sloution just to know different approach most of them are creating new linked list which is extra space i have stored my result in the linkedlist which has max length of question it is right to do so ? or i shouldn't modify the question's linked list..

@pankajyadav-en7tb 8 ай бұрын

Wow!!.

@kidoo1567 10 ай бұрын

Always we search for nikil's leetcode solution ❤😅

@nikoo28 9 ай бұрын

wow...I am grateful for that.

@worthyvibes9989 2 ай бұрын

In problem values are 5 and 2 are giving for sum then ? carry = sum /10; -> 7/10 = 0.7; why sum is saving -> sum %10 ?? any one know ?

@ilmanti 7 ай бұрын

Great explanation! Could you please explain how result contains the numbers if we're only assigning the numbers in the next for the ptr?

@nikoo28 7 ай бұрын

the result does not contains numbers, it contains a linked list, that has the answer numbers. That is what the question asks as well :)

@ilmanti 7 ай бұрын

@nikoo28 I understand, I used nunbers by mistake. What I meant is how does it contain the full linked list if we're only updating the ptr linked list? Hope that clears up the question!

@nikoo28 5 ай бұрын

It still has single digits, you will have to interpret/construct the number from the list

@user-um2tl3mn5t 6 ай бұрын

In the above case missing some test cases when both linked sizes are not the same that time above code will not work. Other your explanation is superb. add this code and sum variable will be global while(l2 != null){ sum = 0 + carry; sum += l2.val; l2 = l2.next; carry = sum / 10; sum = sum % 10; ptr.next = new ListNode(sum); ptr = ptr.next; } while(l1 != null){ sum = 0 + carry; sum += l1.val; l1 = l1.next; carry = sum / 10; sum = sum % 10; ptr.next = new ListNode(sum); ptr = ptr.next; }

@nikoo28 6 ай бұрын

It will work, did you check the code available on Github?

@evliyabilmemkimhazretleri9811 5 ай бұрын

thanks for the explanation.

@naveennaidu4855 11 ай бұрын

sir suppose in the last Iteration carry is more than one than what happens. in your code how can you decide carry is one... ?

@nikoo28 10 ай бұрын

when you are adding 2 single digits, the carry can never be more than 1 :)

@armaan8449 4 ай бұрын

I had the same question but, two single digits can't have carry more than 1

@jjoelthomas 5 ай бұрын

Great tutorial. Just a small suggestion. int sum = 0 + carry; Is this needed? If 0 is going to be added every time in the loop we can just ignore it and write it like int sum = carry. I tried and it worked. Only if we need to add sum to sum then we need to write like int sum = sum + carry; otherwise I feel the 0 is redundant. Your thoughts on this please!!!

@nikoo28 4 ай бұрын

0 + carry just seems familiar with what we are doing in the future. Makes your code more readable.

@reyazahmed4855 Жыл бұрын

Yet another dsa channel. Same story different actor

@boubacarboulkassoum2804 Жыл бұрын

Amazing bro keep going!! Love what you're doing. How can I contact you pls?

@nikoo28 Жыл бұрын

You can contact me via e-mail. It is available in the "About" section of my channel :)

@alejandrogonzalezalmazan3432 Жыл бұрын

Wouldn’t the first element in your solution node (zero) affect the final result? I didn’t get that

@nikoo28 Жыл бұрын

In the provided code, the initial node with value 0 is actually a placeholder node. This is a common technique used in linked list problems to simplify the code and avoid special cases at the beginning of the list. It doesn't affect the final result of the summation. As the code processes the linked lists l1 and l2, the actual result is constructed starting from the node after the placeholder node. This is why, throughout the loop, new nodes are added after the placeholder node (since the code initializes ptr as result). The code returns result.next, which is the node immediately after the placeholder node. This is the correct starting point for the final result linked list.

@user-oj8ey7wc2n Ай бұрын

why we should add sum in the ptr.next?in think we should add in ptr.next.val ?

@nikoo28 Ай бұрын

can you tell me the timestamp you are referring to?

@laxmanpatelpatel4657 Жыл бұрын

can you help do this type of question solution

@nikoo28 11 ай бұрын

can you please elaborate?

@YeaminiNawal Жыл бұрын

it was really helpful. thank you. just wanted to say that if the audio was clear it would have been more convenient, as ur voice feels like an echo. overall thanks

@thisisaniketup 6 ай бұрын

How will this eliminate the problem of test cases of very large numbers?

@nikoo28 5 ай бұрын

because you are using linked lists. Each node will have only 1 digits. So your number can have 1000 digits, and still you will be able to add

@anubhav.codess 7 ай бұрын

if(carry>0) { ptr.next=new Node(carry); } what if the value of carry is 2 or 3 or 4 ?

@nikoo28 7 ай бұрын

When you add 2 digits, can the value of carry ever be more than 1 ??

@DataWorld1199 8 ай бұрын

This is a question for this problem. if l1 has more nodes than l2, then l2 next node is null. if number+null, we will get null? We should consider this situation. is it?

@nikoo28 8 ай бұрын

check the problem constraints. You may need to modify your code accordingly :)

@suneosama939 9 ай бұрын

Hey bro i have a quesiton, why result next have the sum of ptr have add? I don't understand and question 2 is why you return head next instead of ptr next? Hmm maybe ptr next just a single node and result next all the node that ptr next have? Why result have all the sum that ptr next add, hmmm can you explain

@nikoo28 8 ай бұрын

can you explain your question with an example? I am unable to follow your doubt.

@suneosama939 7 ай бұрын

Its mean brother you're so good, understand that brother 😂😆

@Novakid04 8 ай бұрын

I dont understand why when we return result.next we get something iw we didnt add anything in it.

@nikoo28 7 ай бұрын

result.next has the complete linked list

@Novakid04 7 ай бұрын

@@nikoo28 Thank you, I figured it out after some time.

@krsvlog1742 4 ай бұрын

code didn't worked on leetcode man what to do ?

@nikoo28 4 ай бұрын

that is not possible. try the code available on github (link in description)

@hermionegrangerleviosa870 Жыл бұрын

Bro can you explain same problem by using python

@nikoo28 Жыл бұрын

the logic will remain the same, it gets a little hard to solve for every language

@chuckynorris616 8 ай бұрын

praise lord ganesh

@nikoo28 7 ай бұрын

🙏

@arijitmalakar6911 Ай бұрын

This solution is giving "time limit exceeded" error n leetcode...

@code-Dude 4 ай бұрын

can someone help me /** * Definition for singly-linked list. * public class ListNode { * int val; * ListNode next; * ListNode() {} * ListNode(int val) { this.val = val; } * ListNode(int val, ListNode next) { this.val = val; this.next = next; } * } */ class Solution { public ListNode addTwoNumbers(ListNode l1, ListNode l2) { l1 = revesrseLL(l1); l2 = revesrseLL(l2); ListNode head = new ListNode(0); ListNode temp = head; int carry = 0; while( l1 != null || l2 != null ){ int sum = carry; if(l1 != null){ sum = sum + l1.val; l1 = l1.next; } if(l2 != null){ sum = sum + l2.val; l2 = l2.next; } //check carry and sum carry = sum / 10; sum = sum % 10; temp.next = new ListNode(sum); temp = temp.next; sum = 0; } if(carry==1){ temp.next = new ListNode(1); } return head.next; } public ListNode revesrseLL(ListNode head) { ListNode pre = null; ListNode cur = head; ListNode nxt; while (cur != null) { nxt = cur.next; cur.next = pre; pre = cur; cur = nxt; } return pre; } }

@priyarani306 5 ай бұрын

Which language has he used?

@nikoo28 5 ай бұрын

JAVA

@usmanrangrez-cd7zj Жыл бұрын

class Solution { public: ListNode* addTwoNumbers(ListNode* l1, ListNode* l2) { ListNode *ans = new ListNode(0); ListNode *curr=ans; ListNode *p=l1; ListNode *q=l2; int carry = 0; while(p!=NULL || q!=NULL){ int firstData = (p!=NULL)?p->val:0; int secondData = (q!=NULL)?q->val:0; int sum=firstData+secondData+carry; carry=sum/10; int toPut = sum%10; curr->next = new ListNode(toPut); curr=curr->next; if(p!=NULL) p = p->next; if(q!=NULL) q = q->next; } //end pe agar carry milega 1 if(carry>0){ curr->next = new ListNode(carry); } return ans->next; } }; Different Approach