Add Two Numbers (LeetCode 2) | Full solution with diagrams | EASIEST EVER | Study Algorithms
Vložit
- čas přidán 22. 07. 2024
- 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...
📖 Reference Books:
Starting Learn to Code: amzn.to/36pU0JO
Favorite book to understand algorithms: amzn.to/39w3YLS
Favorite book for data structures: amzn.to/3oAVBTk
Get started for interview preparation: amzn.to/39ysbkJ
🎥 My Recording Gear:
Recording Light: amzn.to/3pAqh8O
Microphone: amzn.to/2MCX7qU
Recording Camera: amzn.to/3alg9Ky
Tablet to sketch and draw: amzn.to/3pM6Bi4
Surface Pen: amzn.to/3pv6tTs
Laptop to edit videos: amzn.to/2LYpMqn
💻 Get Social 💻
Follow on Facebook at: / studyalgos
Follow on Twitter at: / studyalgorithms
Follow on Tumblr at: / studyalgos
Subscribe to RSS feeds: studyalgorithms.com/feed/
Join fan mail: eepurl.com/g9Dadv
#leetcode #programming #interview
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.
i really enjoy your leetcode explanations with the dry run of the code. as somone prepping for interviews, youve helped me a lot. thankyou!!!
This is the best and clearest explanation of a leetcode problem that I have ever seen !!!
you are truly a gem for DSA learners .
Really easy to understand explanation and the best I have seen for this problem, thank you so much!
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!
You're very welcome!
Your solution made the most sense to me. Thanks!
very clear explanation brother ..I so great to find your videos
bruh you are awesome not even get bored while watching
thanks
Thank you brother your explanation is amazing . i understood this problem very clearly
nice explanation, got understood the solution in one video of yours,despite searching others
glad you found it helpful
this was a beautiful explanation. Thank you
You deserve many more subscribers 😃Concise and accurate explanation.
No confusion, every point makes sense. Please keep up the good work. 👍
Trying hard 😇
This man explains Best of best on youtube,Huge Salute 👑👑👑👑
so glad you feel this way.
Your leet code solutions are above the par and the explaination is the deadly combination
So happy to hear that :)
I Felt Happy After Listening This
Thank You Bro
You are really teaching amazing sir, I can undestand very clearly❤
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🤩🤩😍😍👏👏
Thank you !
You make best explanations :)
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
thanks for the sub 😄
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.
Well done
Muito Obrigado por essa Explicação fantastica !!!
Very well explained. Thanks
Good work, Keep it up!
great explanation! so easy to follow :)
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
glad you found it helpful
Частично понимал перевод, но за счет очень классного визуального объяснения понял объясняемый алгоритм. Круто, спасибо, было интересно
Я так рада, что смогла вам помочь.
Amazing content bro keep going, only time is your enemy, just wait for some time and you will reach to new heights.
Hope so
Thanks. very cool video
thanks for the great explanation.
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..
Beautiful explanation..🔥🔥
Best explanation to this i have seen so far
yay!!
Thankyou sir 😊😊
explained simply! thank you
Glad it was helpful!
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 ?
understood thanks !
awesome explanation bro
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.
nicely explained ,thank you
Glad it was helpful!
How will this eliminate the problem of test cases of very large numbers?
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
thanku so much
why we should add sum in the ptr.next?in think we should add in ptr.next.val ?
can you tell me the timestamp you are referring to?
Always we search for nikil's leetcode solution ❤😅
wow...I am grateful for that.
Wouldn’t the first element in your solution node (zero) affect the final result? I didn’t get that
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.
Thank you
sir suppose in the last Iteration carry is more than one than what happens. in your code how can you decide carry is one... ?
when you are adding 2 single digits, the carry can never be more than 1 :)
I had the same question but, two single digits can't have carry more than 1
if(carry>0)
{
ptr.next=new Node(carry);
}
what if the value of carry is 2 or 3 or 4 ?
When you add 2 digits, can the value of carry ever be more than 1 ??
Great explanation! Could you please explain how result contains the numbers if we're only assigning the numbers in the next for the ptr?
the result does not contains numbers, it contains a linked list, that has the answer numbers. That is what the question asks as well :)
@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!
It still has single digits, you will have to interpret/construct the number from the list
thank u so much.your explanation is quite simple
Happy to help
@@nikoo28 but why not all medium questions in leetcode have videos.i suggest to increase number of medium questions
@@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 :)
@@nikoo28 thank you so much.appreciated
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
can you help do this type of question solution
can you please elaborate?
Yet another dsa channel. Same story different actor
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?
check the problem constraints. You may need to modify your code accordingly :)
Worth the time
appreciate your feedback
I dont understand why when we return result.next we get something iw we didnt add anything in it.
result.next has the complete linked list
@@nikoo28 Thank you, I figured it out after some time.
code didn't worked on leetcode man what to do ?
that is not possible. try the code available on github (link in description)
Thanks
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!!!
0 + carry just seems familiar with what we are doing in the future. Makes your code more readable.
Amazing bro keep going!! Love what you're doing. How can I contact you pls?
You can contact me via e-mail. It is available in the "About" section of my channel :)
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
can you explain your question with an example? I am unable to follow your doubt.
Its mean brother you're so good, understand that brother 😂😆
Bro can you explain same problem by using python
the logic will remain the same, it gets a little hard to solve for every language
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;
}
It will work, did you check the code available on Github?
thanks for the explanation.
Wow!!.
This solution is giving "time limit exceeded" error n leetcode...
Which language has he used?
JAVA
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;
}
}
I must be doing something wrong, but all my test cases come back as wrong with this code.
It adds an extra 0 to the beginning of the list each time. I'm not sure how or why?
Did you have a look at the code given in video description?
praise lord ganesh
🙏
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