Merge K sorted Lists - Solution | Hashmap and Heap | Data Structure and Algorithms in JAVA

[@aasheesh6001]

Bro dropped the best explanation for priority Queue and think we won't notice.

[@subhammahanta3433]

We need more teachers like you sir...!!(Who will never let the students get bored)......agar ese teacher mil gaye to India a future bright h

[@Pepcoding]

Keep learning. And for better experience, visit nados.io, where you will get well curated content and career opportunities.

[@a.techsys9389]

@subham right brother.

[@sanatasneem2674]

This is some whole other level 😲😲😲😲 Kabhi socha bhi nahi hoga ki ayese bhi koi samjha sakta hai!

[@itachiuchiha-vs3qb]

WOW! your way of implementing code with explaining clear thought process is legendary. .

[@sauravdas7591]

is it only me, or the audio sounds a bit jittery? very light distortion in audio

[@rohankaran0079]

Sir ap bhagvan hai aise koi samjha hi nai skta hai No content is upto this level in any platform for DSA i bet

[@MYSTERIOUS_BOY_1]

The best.......................sir❤ Literally NO WORDS...😮 FOR YOUR EXPLAINATION ❤

[@somnathroy6251]

Man this is so good, I regret founding this channel so late.

[@Pepcoding]

Hope we help you but for better experience and well organised content visit - nados.io 🚀 ⚠️ You can also post your queries on community tab.

[@sharuk3545]

next level explanation with the help of this solution i did it merge K LinkedList problem

[@namantiwari8251]

That's Mind Blowing 💯💯

[@aayush481]

epic man, no one tells how internally comareTo works !

[@pramodbasu7732]

5 days back this question was asked to me in VMWARE coding round

[@rishabhgoyal2835]

next level explanation , thank you : )

[@Pepcoding]

Thank you so much. Keep learning

[@sonipra2376]

Splendid Explanation.

[@Pepcoding]

Thankyou beta! I am glad you liked it. If you like our efforts, will you like to write a few words about us here (www.quora.com/How-do-I-start-learning-or-strengthen-my-knowledge-of-data-structures-and-algorithms )

[@mihirsaini592]

Great explanation as always.

[@mickyman753]

instead or writing comparator or comparable ,use this PriorityQueue pq=new PriorityQueue((p,q)->{ return p.val-q.val; });

[@shrad6611]

pure content video sirf kaam ki chize karte ho aur logo ki tarah bakwas nahi luv the video

[@Pepcoding]

Thankyou beta! I am glad. Your kind words are the kind of motivation that truly help me in making more and more content. Especially, these days, not everybody is generous with motivating anybody either. It means a lot. If you like our efforts, will you like to write a few words about us here (www.quora.com/What-are-the-good-websites-to-learn-data-structures-and-algorithms ) Keep learning and keep loving Pepcoding😊

[@shrad6611]

@@Pepcoding yeah sure

[@chandrashekharagrawal4890]

Woww, this is amazing.

[@pranshulkharniwal8146]

majha aa gya sir✨✨✨✨

[@Pepcoding]

Thankyou beta! I am glad you liked it. I hope that you are watching till the end and trying to understand what, how, and especially why of the problem. If you like our efforts, will you like to write a few words about us here (www.quora.com/What-are-the-good-websites-to-learn-data-structures-and-algorithms )

[@ashwinnema06]

Nice explanation sir

[@anirudhatalmale5575]

very well explained

[@Pepcoding]

Glad you think so and If you like our efforts, please upvote the comments written by the students about Pepcoding here (www.quora.com/What-are-the-good-websites-to-learn-data-structures-and-algorithms )

[@animetimes5563]

OP level explanation

[@Pepcoding]

Glad to know, that you love the explanation, for better experience and precisely arranged videos. Visit - nados.pepcoding.com and sign up to NADOS. Don't forget to follow us on Instagram instagram.com/pepcoding/

[@amandixit3555]

public static ArrayList mergeKSortedLists(ArrayList list) { ArrayList rv = new ArrayList(); PriorityQueue pq=new PriorityQueue(); for(int i=0;i0) { rv.add(pq.remove()); } return rv; } sir can we do like this.

[@samirray7544]

understood it very well.......very informative video...........

[@Pepcoding]

Thankyou beta! I am glad you liked it. I also hope that you are watching till end. Will you like to write a few words about us here (www.quora.com/Which-is-the-best-online-course-to-learn-data-structures)

[@samirray7544]

@@Pepcoding Sir it says page not found

[@nextgeneration2835]

just to the point :) thank you

[@Pepcoding]

Glad it helped!

[@jsuryakt]

awesome explanation

[@Pepcoding]

Glad it was helpful! Keep learning. And for better experience, visit nados.io, where you will get well curated content and career opportunities.

[@abhishekvishwakarma9045]

Great Explanation sir get multiple topics (Interface) also 👌🔥

[@Pepcoding]

Glad to know that you liked the content and thank you for appreciating. If you like our efforts, will you like to review us here - g.page/Pepcoding/review?rc

[@utkarshsharma1185]

thanks sir...

[@ghanibhai1630]

i have used hashmap + priority queue

[@runtime379]

great sir

[@gauravagarwal6565]

what about : for(int i = 0;i

[@bloody9162]

TC: nlogn where n is the length of all lists combined, using heaps/pq tc gets reduced to nlogk where k is the size of lists array

[@deepakjoshi4318]

Sir Fractional knapsack ki video nhi dali hai apne?

[@ankitparashar8730]

Explanation level

[@Pepcoding]

If you like our efforts, please upvote the comments written by the students about Pepcoding here (www.quora.com/What-are-the-good-websites-to-learn-data-structures-and-algorithms )

[@RishabhJain-hr6sz]

Sir, not able to find fractional knapsack problem on channel. Could you please share the link, since you mentioned in this video. Thanks!

[@mehulbisht9708]

sir to implement an interface in java in android studio we need to annotate the function ( which is declared inside interface ) with @override. Isn't that required for java programs outside android studio ?

[@Pepcoding]

@override is not mandatory beta. Not even in android.

[@mehulbisht9708]

@@Pepcoding ok thankyou sir

[@VISHNUVardhan-mr2cq]

Sir, u have not uploaded fractional knapsack?

[@Pepcoding]

beta daal denge.

[@shreeyagupta8472]

Sir what if we add all the elements of all the arrays in priority queue and then peek and remove them all?

[@1piecegaming622]

hey..are you following the babbar bhaiya DSA sheet??

[@NitinSharma-bk7dw]

Complexity will be high if you do so because inserting an element in pq takes log(n). For k^2 element it will be k^2 log k + k^2 iterations for inserting in pq

[@hymnish_you]

Sir, why didn't u use this simple method? public static ArrayList mergeKSortedLists(ArrayList lists){ PriorityQueue pq = new PriorityQueue(); for(ArrayList ls : lists){ for(int num : ls){ pq.offer(num); } } ArrayList rv = new ArrayList(); while(pq.size() != 0){ rv.add(pq.poll()); } return rv; }

[@RishabhJain-hr6sz]

Amazing!

[@Pepcoding]

Thank you! Cheers!

[@satvrii]

❤

[@surajpatil2879]

PriorityQueue pq = new PriorityQueue(); for(int i=0;i

[@abhishekjaswal4415]

what if we add all the elements into a priority queue and simply remove elements from priority queue and just return it its working for me but I guess the time complexity will increase?is it?

[@himanshumishra8181]

Nah not sure about the time complexity but the space complexity is goona get O(sum of size of all arrays ) compared to O(k)

[@Pepcoding]

Visit - nados.pepcoding.com and sign up to NADOS. You can ask your doubts on community tab. There are lots of programmers and mentors who can help you out with such doubts. Don't forget to follow us on Instagram instagram.com/pepcoding/

[@factsstats3959]

Can't we just store all values in the Prority Queue First and remove them one by one and print them while removing?

[@nishantchaudhary7902]

can anyone please give me the link of fractional knapsak i'm unable to find it..

[@abhishekverma-se6vw]

Sir when are you uploading level up?

[@Pepcoding]

beta ek week baad

[@anjneykumarsingh4461]

Bhai foundation toh pura krne de sir ko bhut cheez baki h

[@ashishm8850]

Unda!

[@Pepcoding]

Thankyou beta! Keep learning and keep watching😊

[@RiteshKumar-nt5sj]

compare to k andar pair other kya h? this to pair class ka value hai but other? \

[@Pepcoding]

For clearing all your doubts and for best experience, visit on nados.pepcoding.com Don't forget to follow us on Instagram instagram.com/pepcoding/

[@hungryhunter6210]

Sir C++ mein objects ki priority queue k liye comparable kaise likhte hai?

[@Pepcoding]

wahan operator overloading ek rasta hai, doosra functor hota hai. Operator overloading is the usual way.

[@hungryhunter6210]

Thank you for the reply sir.

[@umangchhabra9678]

class Pair { public: int li; int di; int data; Pair(int li,int di,int data) { this->li=li; this->di=di; this->data=data; } }; class FunctorCompare { public: bool operator()(Pair a,Pair b) { return a.data>b.data; } }; priority_queue pq;

[@shubhamsood1406]

@@umangchhabra9678 Can you share your C++ code for this question, I wrote a code but it is not working bcoz of some errors

[@akshatbhaskar5711]

Can anyone please help me telling that what will be complexities of this solution? Btw best video

[@Pepcoding]

Nlogk

[@satyam18_]

Sir cant we simply add all list in a priority queue and then print the priority queue ??

[@Pepcoding]

space jyada lag jaega. O(k) space allowed tha

[@creativegiant148]

It is bfs Kindoff

[@prakritidevverma4315]

Can we do all this in O(1) memory ?

[@Pepcoding]

Beta, I regret to inform you that, I won't be able to answer/solve the personal doubts of each and every student over here. For clearing your doubts, you can join our community on telegram - t.me/pepcoding.

[@prakritidevverma4315]

@@Pepcoding cool, I'll ask over there.

[@indranilchakraborty5949]

Sir fractional knapsack ka vedio nhi hai pepcoding ka ....

[@sauravdas7591]

aditya verma ka dekh lo video

[@raviashwin1157]

@@sauravdas7591 fractional greedy se hota hai wo nahi padhaya aditya verma ne

[@varunsde9533]

I have solved this by using stream API in Java 8 ArrayList result = lists.stream.flatMap(x->x.stream()).sorted.collect(Collectors.toCollection(ArrayList::new));

[@yelp9359]

Sir iski complexity kya hogi?

[@Pepcoding]

nlogk

[@hdang1997]

@@Pepcoding where n is total number of elements in all the arrays, correct?

[@namanmittal9403]

@@hdang1997 where n is the number of elements in the longest list and logk is for the priority queue (enque/deque) ignoring the number of list i.e since k

[@ayushgoel9584]

sir heaps ke questions mein confidence nhi aaya, i hope we will do atleast 20 more problems in LU+IP

[@Pepcoding]

we have a lot many in lu + ip. i think 100 ke kareeb hain, hashmap aur heaps mila ke

[@imavij12]

Ye other ki value kaha se aa rhi h. Compare this ko kis se karega samajh nahi aa rha

[@Pepcoding]

For better insight, visit nados.pepcoding.com, post your doubts, community will help you out there.

[@sarfinawalksh503]

Sir, u have not uploaded fractional knapsack?

[@Pepcoding]

hanji beta, hashmap-heaps ke liye chodda tha firr choot he gya. karna hai

[@sarfinawalksh503]

@@Pepcoding ok sir