Lecture 51: Add 2 Numbers represented by Linked Lists || C++ Placement Course

[@CodeHelp]

Do Visit Relevel: relvl.co/s9q2

[@udaypratapsingh8923]

*babbar bhaiya no. 1*

[@ayushbudhlakoti2004]

bhaiya ...agar hum ans wale function m insertAtHead krde toh last mai ans wali list ko reverse nhi karna padhega ,,,which will save time.....please check and reply

[@mehulsaraswat2688]

Course achi trh se follow kr rha hu. Party zaroor dunga placement k baad. Thankuu bhaiya 👍

[@divashgupta5871]

Mujhe bhi de dena bro😅😁

[@nikhilrana9825]

muje bhi bro

[@ankitmusic13]

hua bhai placement?????

[@Akash-yr2if]

Hua Placement

[@akshaykumar192]

Ho gya placement ?

[@manishrawat3791]

Bhaiya consistency ++ .... bhaiya vase ek baat volu toh ajj kal quality ek number mil rhi hai phele bh milti th vase . Aur sach btau toh khud se man kr rha hai ki kuch kru.. and you will not believe me I have solved more than 180+ question in last 2 months . and before 2 month I am not even able to understand the concept of question . So big thanks bhaiya I really love your videos

[@anshraj2196]

Plz suggest me , I am in second semester currently am learning c++ . So Can I start DSA course side by side with c++ or first i should complete c++

[@cs_in_10_minutes]

bhai, kahan pe job lagi aapki?

[@9852963775aaa]

in love with this series >>>>>>>>

[@mohdtalib934]

we can use insertAtHead then we don't need to reverse the ans LL; nice video bhaiya

[@shubhampatel_2745]

wow amazing point really appreciation you.

[@lakshsinghania]

bro, this code doesnt work on leetcode idk why i tried a lot still

[@ayushbudhlakoti2004]

bhaiya ...agar hum ans wale function m insertAtHead krde toh last mai ans wali list ko reverse nhi karna padhega ,,,which will save time.....please check and reply

[@priyanshukumarsah2746]

nice observation bro ! good keep it up 😇

[@karanborana8540]

Hats off to your consistency and quality of the videos! ❤️💯 Totally loving it!

[@ayushbudhlakoti2004]

bhaiya ...agar hum ans wale function m insertAtHead krde toh last mai ans wali list ko reverse nhi karna padhega ,,,which will save time.....please check and reply

[@divyagupta6854]

I was little bit confused at a different approach I saw where reversal was not done. But doing reversal really makes this problem simple enough to understand and solve. Thanks for this approach.

[@ayushbudhlakoti2004]

bhaiya ...agar hum ans wale function m insertAtHead krde toh last mai ans wali list ko reverse nhi karna padhega ,,,which will save time.....please check and reply

[@vanshgambhir7805]

Anyone who is trying to solve this question now getting stuck it is because test cases have changed i guess so add these lines before returning your ans pointer in your addtwolists function while((ans->data)==0&&ans->next!=NULL){ Node* temp=ans; delete(temp); ans=ans->next; }

[@aryansemwal2472]

can you provide me a full length code ?

[@vanshgambhir7805]

@@aryansemwal2472 class Solution { private: void insertAtTail(struct Node* &head,struct Node* &tail,int val){ Node* temp=new Node(val); if(head==NULL){ head=temp; tail=temp; return; } else{ tail->next=temp; tail=temp; } } struct Node* add(struct Node* first,struct Node* second){ int carry=0; Node* anshead=NULL; Node* anstail=NULL; while(first!=NULL || second!=NULL||carry!=0){ int val1=0; if(first!=NULL){ val1=first->data; } int val2=0; if(second!=NULL){ val2=second->data; } int sum=val1+val2+carry; int digit=sum%10; insertAtTail(anshead,anstail,digit); carry=sum/10; if(first!=NULL){ first=first->next; } if(second!=NULL){ second=second->next; } } return anshead; } Node* reverse(Node* head){ Node* curr=head; Node* prev=NULL; Node* next=NULL; while(curr!=NULL){ next=curr->next; curr->next=prev; prev=curr; curr=next; } return prev; } public: //Function to add two numbers represented by linked list. struct Node* addTwoLists(struct Node* num1, struct Node* num2) { // code here num1=reverse(num1); num2=reverse(num2); Node* ans=add(num1,num2); ans=reverse(ans); while((ans->data)==0&&ans->next!=NULL){ Node* temp=ans; delete(temp); ans=ans->next; } return ans; } };

[@thebhrotherslakshya2005]

thanks bhai , thoda sa explain bhi kar do yarr..

[@vanshgambhir7805]

@@thebhrotherslakshya2005 you can try running the code without it by only writing bhaiya's approach and you will eventually if you try the test cases and carefully observe u will get 0 is not needed at start which is logically correct if we are adding two numbers but using the approach shown in video we are reversing and there is a chance we will get zero at the starting so i wrote an additional line so that all zero's at starting gets deleted and it's important to check if it doesn't reach the null pointer that's it observation is the key while solving and debugging do dry runs

[@thebhrotherslakshya2005]

Thanks bhai.. for explanation

[@jagratgupta8392]

bhaiya generic code part was the best ...........best course for linked list ....thanks bhaiya

[@AgamRaj-p5q]

Now I complete lecture 51 still energetic like 1st one becoz of your ultimate energy and teaching skills

[@ujwalbarodia4313]

Bhaiya done pura up to date hogya bht back log tha Ab ek dum tym pe naya video dekhege Bhiaya meko lagta hai views kam hue uska reason logon ka backlog hai to aap continue krte raho ye KZbin ka best course hai and maybe best free course available.... Thank you bhaiya Attendance++;

[@ayushbudhlakoti2004]

bhaiya ...agar hum ans wale function m insertAtHead krde toh last mai ans wali list ko reverse nhi karna padhega ,,,which will save time.....please check and reply

[@RohitRana-tz2lr]

Bhaiya consistency++... Thank you so much bhaiya for all of your hardwork and dedication ... lucky to get a mentor like you

[@ayushbudhlakoti2004]

bhaiya ...agar hum ans wale function m insertAtHead krde toh last mai ans wali list ko reverse nhi karna padhega ,,,which will save time.....please check and reply

[@itskaaryan7]

thank u love babbar bhaiya for such precious lectures.

[@vipulagarwal2996]

thanku so much babbar bhaiya for the amazing lectures👍👍

[@subhambasuroychowdhury9698]

Awesome video, was able to write the code just after listening to the Problem Statement with the NULL checks and edge cases. Thank you very much

[@ujjwalverma_]

Maja aa gya Bhaiya waiting for next video

[@rawat_ji5183]

perfect explanation bhiya ❤

[@shazeflon1448]

Hi bro currently you are on which lecture?

[@rawat_ji5183]

@@shazeflon1448 topic :- Binary trees 67

[@shazeflon1448]

Great yaar , I'll start stacks ...bro can i discuss with you the approach of some questions I'm kinda getting stuck at if you don't mind

[@rawat_ji5183]

@@shazeflon1448 sure

[@shazeflon1448]

Okay great

[@sushovanchakraborty4908]

Sab samaj AA gaya best explanation sir

[@abhirajbais5093]

bhot mast style hai seekhane ka aapka..SAmay ko samay do ..sb samjh aane lgega..Mazzaa aa rha hai series mai bhot

[@ayushgoel01]

🔴LeetCode Solution:- class Solution { private: void insertAtTail(ListNode* &head, ListNode* &tail, int val){ ListNode* temp = new ListNode(val); if(head == NULL){ head = temp; tail = temp; } else{ tail -> next = temp; tail = temp; } } ListNode* add(ListNode* l1, ListNode* l2){ int carry = 0; ListNode* ansHead = NULL; ListNode* ansTail = NULL; while(l1 != NULL || l2 != NULL || carry != 0){ int val1 = 0; if(l1 != NULL){ val1 = l1 -> val; } int val2 = 0; if(l2 != NULL){ val2 = l2 -> val; } int sum = carry + val1 + val2; int digit = sum % 10; insertAtTail(ansHead, ansTail, digit); carry = sum / 10; if(l1 != NULL){ l1 = l1 -> next; } if(l2 != NULL){ l2 = l2 -> next; } } return ansHead; } public: ListNode* addTwoNumbers(ListNode* l1, ListNode* l2) { ListNode* ans = add(l1,l2); return ans; } };

[@abhiroopsingh9320]

This can be done in O(1) Space Complexity. Please Bhaiya Give us the most optimized approach till the end. This is the solution for LeetCode question. To use this logic for gfg question we just need to pass heads of lists into reverse function and then perform all operations below. class Solution { public: ListNode* addTwoNumbers(ListNode* l1, ListNode* l2) { ListNode* temp1=l1; ListNode* temp2=l2; ListNode* newHead=new ListNode(0); ListNode* ans=newHead; int carry=0; while(temp1!=NULL and temp2!=NULL){ int total=temp1->val+temp2->val+carry; temp1->val=total%10; carry=total/10; ans->next=temp1; ans=ans->next; temp1=temp1->next; temp2=temp2->next; } while(temp1!=NULL){ int total=temp1->val+carry; temp1->val=total%10; carry=total/10; ans->next=temp1; ans=ans->next; temp1=temp1->next; } while(temp2!=NULL){ int total=temp2->val+carry; temp2->val = total%10; carry=total/10; ans->next=temp2; ans=ans->next; temp2=temp2->next; } if(carry!=0){ ans->next=new ListNode(carry); } return newHead->next; } };

[@kundanmali2405]

Thank you for such grt content bhaiya

[@ankurharshit2629]

instead of doing insert at tail, we can do insert at head, then no need to reverse the list

[@anshumansharma1069]

maza aagaya sirr✌✌

[@ITA__EshanTiwari]

Sir ghoom diya is que ne 😵

[@vinayakk2745]

better approach: pehle dono linked lists ko numbers mein convert karo, then un numbers ko add karke jo result aayega, use new linked list bana lo, eeeaaazy

[@inter3988]

@@vinayakk2745 yeah....easy approach. what if the linked list is of 500 length? where will you store the sum? in long long int? I doubt so..

[@abhyaskanaujia3862]

Thank you for all your efforts. You're the best.

[@ayushbudhlakoti2004]

bhaiya ...agar hum ans wale function m insertAtHead krde toh last mai ans wali list ko reverse nhi karna padhega ,,,which will save time.....please check and reply

[@108_adityakumar6]

Your linked list series is best.Thanks bhaiya 🔥🔥

[@ahmadrasheed2598]

use this to remove leading zeros in answer list: while (ans != NULL && ans->data == 0) { Node* temp = ans; ans = ans->next; delete temp; // Free the memory of the leading zero node }

[@anuptewary3016]

Present bhaiya with lot's of fire and love 🔥

[@ayushbudhlakoti2004]

bhaiya ...agar hum ans wale function m insertAtHead krde toh last mai ans wali list ko reverse nhi karna padhega ,,,which will save time.....please check and reply

[@suyashvikramsingh8913]

bhaiya much2 better than paid courses ,thank u bhaiya

[@Nikhil-ke9bq]

You are the best bhaiya, placement lagne k baad linkedin pe mention krunga🤩🤩👍

[@AA-wy9vw]

Loving the series!!

[@ayushbudhlakoti2004]

bhaiya ...agar hum ans wale function m insertAtHead krde toh last mai ans wali list ko reverse nhi karna padhega ,,,which will save time.....please check and reply

[@udaypratapsingh8923]

bhaiya doubly linked list ke bhi karva dijiye 🔥🔥🔥🔥🔥.. course op 🔥🔥🔥🔥

[@ravishekhawat5958]

2nd approach .. Dono link list ke number 2 var me store kr lo .. dono ko sum kro .. And sum se ek ek number extract krke new link list me daal do 🙂

[@kumarpawansahh]

Bhaiya aapka jitna shukriya da karu utna kamm hai

[@prashantbirajdar9271]

wahh bhaiyaa maza aa gya sub smj aa gyaa❤❤👍👍

[@avibirla9863]

Bhaiya ka new dialogue : RYTHM BREAK NA HO TOH APNE SPONSORS KO SHOUTOUT DE DETE H 😂😎

[@CodeHelp]

😂

[@Shivam-wl7fg]

Node* getReverse(Node* head){ Node* prev = NULL; Node* curr = head; Node* next = NULL; while(curr != NULL){ next = curr->next; curr->next = prev; prev = curr; curr = next; } return prev; } Node* addTwoLists2(Node* first, Node* second){ // step 1: reverse giveen linked lists Node* head1 = getReverse(first); Node* head2 = getReverse(second); int x; int y; int carry = 0; int n; Node* ans = NULL; Node* temp = NULL; while(head1 != NULL & head2 != NULL){ x = head1->data; y = head2->data; n = x+y+carry; // update ans list int val = n%10; temp = new Node(val); temp->next = ans; ans = temp; head1 = head1->next; head2 = head2->next; carry = n/10; } while(head1 != NULL){ x = head1->data; n = x+carry; // update ans list int val = n%10; temp = new Node(val); temp->next = ans; ans = temp; head1 = head1->next; carry = n/10; } while(head2 != NULL){ x = head2->data; n = x+carry; // update ans list int val = n%10; temp = new Node(val); temp->next = ans; ans = temp; head2 = head2->next; carry = n/10; } if(carry != 0){ int val = carry; temp = new Node(val); temp->next = ans; ans = temp; } return ans; } this approach is update version of love bhaiya

[@ABHISHEKKUMAR-bx9px]

we could have used insertAtHead directly which reduce the need of reversing the ans list at the end

[@daanyalparbulkar2573]

have you tried it and did it work ❓

[@manavsharma142]

Great explanation as always

[@palaksolanki8037]

Loving the series bhaiya😀😀

[@muskanagarwal8573]

u r the best teacher.. bhaiya😊

[@funwithrayhan9579]

masterclass bhai.. love from bangladesh

[@abhijeetbiswas3017]

code for 1st approach: class Solution { private: Node* reverse(Node* head) { Node *prev = NULL; Node *curr = head; Node *forward = NULL; while(curr != NULL) { forward = curr -> next; curr -> next = prev; prev = curr; curr = forward; } return prev; } void insertAtTail(struct Node* &head, struct Node* &tail, int value) { Node *temp = new Node(value); if(head == NULL) { head = temp; tail = temp; return; } else { tail -> next = temp; tail = temp; } } struct Node* add(struct Node* first, struct Node* second) { int carry = 0; Node *ansHead = NULL; Node *ansTail = NULL; while(first != NULL && second != NULL) { int sum = carry + first -> data + second -> data; int digit = sum % 10; //create node and add in LL insertAtTail(ansHead, ansTail, digit); carry = sum / 10; first = first -> next; second = second -> next; } while(first != NULL) { int sum = carry + first -> data; int digit = sum % 10; //create node and add in LL insertAtTail(ansHead, ansTail, digit); carry = sum / 10; first = first -> next; } while(second != NULL) { int sum = carry + second -> data; int digit = sum % 10; //create node and add in LL insertAtTail(ansHead, ansTail, digit); carry = sum / 10; second = second -> next; } while(carry != 0) { int sum = carry; int digit = sum % 10; //create node and add in LL insertAtTail(ansHead, ansTail, digit); carry = sum / 10; } return ansHead; } public: //Function to add two numbers represented by linked list. struct Node* addTwoLists(struct Node* first, struct Node* second) { // code here\ //step 1 -> REVERSE THE LLS first = reverse(first); second = reverse(second); //step 2 -> add the LLS Node *ans = add(first, second); //step 3 -> REVERSE THE ANS LL ans = reverse(ans); return ans; } };

[@anuptewary3016]

Maja a gye bhaiya video dekh kar waiting for next video ❤️

[@prikshit_sharma4071]

apka naam roshan kruga guruji ❤️

[@aditya_as2]

this course>>>>>>>>>>>>

[@debajyatibanerjee5480]

Bhaiya bura mat maniyega ... apka video dekhte dekhte like karna bhul jata hu... sry for that... but dil se thankuuuu... love u babbar bhaiya....

[@shivanshisharma3718]

Bhaiya your content is awwsmm 👍👍 DBMS start kra. Do

[@utkarshdubey1618]

mast padhate ho bhaiya aap . Dil se sukriya aapka ❤

[@ayushbudhlakoti2004]

bhaiya ...agar hum ans wale function m insertAtHead krde toh last mai ans wali list ko reverse nhi karna padhega ,,,which will save time.....please check and reply

[@mrfactvenger6570]

Bhai stack and queue ke lectures kab aayege,?

[@suvigyabasnotra7378]

Aapke GFG ka timer kyon nahi visible hai?

[@jePastapuramNagashwini]

class Solution { public: //Function to add two numbers represented by linked list. long long int number(Node* head){ Node* temp=head; long long int num=0; while(temp->next!=NULL){ num=(num+temp->data)*10; temp=temp->next; } num=num+temp->data; return num; } struct Node* addTwoLists(struct Node* &first, struct Node* &second) { long long int num=number(first)+number(second); Node* temp=first; while(temp->next!=NULL){ Node* de=temp->next; temp->next=temp->next->next; delete de; } if(num==0){ Node* n=new Node(0); temp=n; temp->next=NULL; return temp; } int i=0; while(num!=0){ Node* newhead=new Node(num%10); num=num/10; if(i==0){ temp=newhead; } else{ newhead->next=temp; temp=newhead; } i++; } return temp; } }; my code is pretty clumsy confusing and difficult but can anyone tell me where I did do wrong. it's not working for long integers

[@vmstudy9965]

Mjaa to aa rha h bhiya...🎉🥳

[@priyanshujain862]

😊😊 thank you bhaiya please continue The important questions of linked list

[@cat-codes1on1]

BHAIYA YE ANSHEAD AUR ANSTAIL KYU BANAYA 15:35 PLEASE EXPLAIN KIJIYE..

[@arpitrajput6424]

Love the series ❤️❤️❤️👍

[@codingindisguise]

An easy method: Traverse linked list1 and find the num1 Traverse linked list 2 and find the num2 Add num1 and num2 = sum Now make a new linked list as an answer! Now take the digits of the sum one by one and put it in the answer waala linked list by inserting every digit at the head.

[@imPriyansh77]

yes, tysm

[@vishnubishnoi4621]

error dega for very large input test cases, just wasted a whole day to make that approach work , though logic is correct.

[@suyashjain3223]

Amazing Video Bhaiyaa 🤩

[@anuradha3868]

Awesome lecture....thanku so much ❤️🙌

[@rudrapratapsinghtomar3925]

Thankyou soo much for providing such a quality content.

[@Akash-yr2if]

I got diagnosed with CANCER after watching this solution. Either I'll leave this question or get other approch. Ye tow merasa yaad nehi rahega

[@devanshusahoo]

Thank You bhaiya for the wonderful videos! You have truly helped me develop a love not just for coding but for learning and exploring as well!

[@ayushbudhlakoti2004]

bhaiya ...agar hum ans wale function m insertAtHead krde toh last mai ans wali list ko reverse nhi karna padhega ,,,which will save time.....please check and reply

[@_A__Mohit]

OP lecture and teacher also 💥💥💥💥💥💥💥💥💥💥

[@computerguy3550]

lAJAVAH aJJ toH maZA hI AHHGYA👌👌👌👌

[@ashutoshgiri2974]

A person name love sharing love at free of cost ❤️ getting so much love from a person falling in love by loving the content of the course

[@hasanrants]

bhaiya sab smjh aagaya, thank you!

[@harshkumar7686]

Last mein optimisation mein maja aa gaya bhaiya . Thank you for your immense support ❤

[@Bhagwati_Jewellers.]

Amazing bhaiya 😍

[@manavsingh5919]

Thank Sir Understood everything 😊

[@rachit_joshi]

Thank You So Much BHRATA SHREE !!!!!

[@sounaksaha1455]

Hello ji Sir, aapke saath saath mera bhi consistency barkarar hai... Baas revision thora a66e se karna padega🥺

[@bhawargujral3574]

Great video bhaiya😍

[@harikrushnasuhagiya3925]

AWESOME VIDEO BANADI BHAIYA

[@tejasshaha6629]

Amazing video Bhaiya ❤❤

[@satyajeetrai6529]

04-09-2023 LECTURE 51

[@manavshah1844]

Very Great Explanation Sir Loved It

[@TheBaljitSingh]

yeha hum privete me kyu likh rahe hai?? public me bhi ho shakta hai na declaration??

[@ayushkushwaha171]

Thanks for the easiest explanation!

[@poojayadav695]

awesome course bhaiya😄😄😄

[@aryankr]

sab sahi char raha hai bhaiya

[@KaushikSharma-c3q]

Awesome explanation.

[@RohitSingh-hc8yi]

Bhot maja aa rah hai bhaiya

[@shubhamkumarsingh8818]

thank you so much bhaiya

[@be_happy8411]

Net slow hai bhaiya motivation nhi, aaj complete krke hi shoduna🔥

[@rahuls1147]

Bhaiya ab leetcode ke qn kyu solve nahi karte

[@roshanansy6901]

test is important bhiya jo mene pa liya .thanks

[@saurabhrajput7492]

EXPLAINING IS SOO GOOD ....LOVE YOU BRO || RESPECT++;

[@shristiiverma1106]

Present Bhaiya 🥳🥳

[@sagarsharma7671]

Thanx bhaiya. Luv U 🤟

[@vikashkumarvlogsnitj]

superb video baiya

[@namansharma44]

Bhaiya please add handwritten notes on lecture 10 and above

[@kundantarafdar3663]

BHAIYYA NE KAHA "COMMENT KARNEKA TOH, KARNE KA...!"😁

[@bhanuverma_iitbhu]

bhaiya directly insert at head nhi kr skte kya ans node me??

[@PRIYANSHUKUMAR-un9zu]

Present bhaiya ❤🔥

[@kaushalkumar01]

Present bhaiya🙋‍♂

[@natureone5617]

BHAIYA CONTEST K SOLUTIONS BHI UPLOAD KAR DO

[@haiderali0801]

Bhai you are literally doing a great work..,...

[@priyanshugoyal2539]

Present Bhaiya JI