Intersection of Two Linked Lists (LeetCode 160) | Full solution with animations | Study Algorithms

A linked list node has 2 dimensions. One is the value of the node and the other is the address. This information is really helpful when solving questions like finding the intersection point of two linked lists. This video explores 2 solutions, where we take advantage of the address of a node and uses a mathematical trick to optimize it. All along with step by step demonstrations and a dry-run of code in JAVA.

Chapters:
00:00 - Intro
01:10 - Problem statement and description
03:15 - Brute Force approach to find the intersection point
06:54 - Time optimized approach to find the intersection
10:07 - Space optimized approach to find the intersection
13:00 - Dry-run of code
15:36 - Final Thoughts

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#leetcode #programming #linkedlists

[adhirajkar]

There are many solution videos available on youtube but ur explanation is the best ever.

[nandiniambajipeta]

wow understood all the approaches . Thank you😌

[rishabhupadhyay]

Thanks brother. You are helping us by the best explanations I have have ever seen... Thanks a lot. Keep working and keep helping... Now I am your new subscriber

[Parth-zk]

Your way of Explaining solution is awesome sir

[Mania_Dev]

Thankyou Nikhil, Your animation explanations are a revelation..wish I'd found your channel sooner!

[ramsidh]

Nicely Explained and good use of animations.

[parthanuj]

i am shocked and amazed by this solution

[sammedpatil]

In every problem "Final thoughts" are awesome....

[ishikagoyal]

thank you sir ... We like the way you explain

[vineetkumar]

Thank you sir for explaining everything thoroughly ❤

[sachinsoma]

First problem I solved without looking at solution🥰

[beemavishnu]

Thanks for your multiple examples.

1) In 3rd example. Small correction. Length of the list 1 is 9 but not 10. So difference is 3 and need to advance to 3 nodes as "head 1" is already at first node.

2) As part of 2nd example, first list is kept in separate array / HashSet. You mentioned second list elements address (M, N, O...) to compare with the address in array / HashSet in O(1). How is this possible. Please let me know if there is any such example for Hash table for linked list.

[Lakshareads]

sorry if i'm wrong, isn;t l1 length 9?

[Sulthanul_Faris]

Sir you are amazing
I love your way of explaining ❤
Sir how can I connect you personally?

[Babas]

qq, is the TC for the first brute force approach you explained 0(m*n)?

[kale-lbpr]

node* intersectionY(node* head1, node* head2) {
if (head1 == NULL || head2 == NULL) return NULL;

node* temp = head1;
map<node*, int> mpp;

// Insert nodes of the first linked list into the map
while (temp != NULL) {
mpp[temp]=1;
temp = temp->next;
}
// Traverse the second linked list and check for intersection
temp = head2;
while (temp != NULL) {
if (mpp.find(temp) != mpp.end())
{
return temp;
}
cout<<temp->data<<" ";
temp = temp->next;
}
return NULL;
}int main()
{
vector<int> arr={3, 1, 4, 6, 2};
vector<int> b={1, 2, 4, 5, 4, 6, 2};
node *head1=convertarrtoLL(arr);
node* head2=convertarrtoLL(b);
node* head=intersectionY(head1, head2);
if (head != nullptr) {
cout << "Intersection found at value: " << head->data << endl;
} else {
cout << "No intersection found." << endl;
}


}1 2 4 5 4 6 2 No intersection found.?? pls tell me why its not coming??imtrying it from past 4 hrs still i can't pinpoint my mistake?

[udayrajvadeghar]

bhaiya i think the length of the linked list 1 is 9 , other than that thank you so much for the solution.

[mahatrt]

I got an error in getListLength(), cannot find symbol is shown
What can i do sir

[RohitKumar-ltg]

what if we have same value before intersection how will that situation be taken care of ways Great Explanation

[az-opoc]

Bro, getListLength is user-defined fn or inbuilt fn?