Recursion Subset, Subsequence, String Questions

[@KunalKushwaha]

DSA + interview preparation playlist: kzbin.info/aero/PL9gnSGHSqcnr_DxHsP7AW9ftq0AtAyYqJ

[@OmkarSriwastva]

plz reply bro

[@amruthaa5876]

If someone had skills like you especially the way you teach, they would launch this course as a paid one. Let it be anyone in this world. But you're here trying to help students like me and I'm very grateful. Thanks a ton, Kunal!

[@Tomharry910]

Dont give him ideas!

[@utkrishtsneh8298]

Atleast the course would've been completed by now had it been paid

[@Jatin-zn1px]

​@@utkrishtsneh8298true

[@shouryakhandelwal6484]

@@utkrishtsneh8298 i am a coding beginner started this course just one month ago, so can you please tell me which things he hadn't taught yet and from where i could learn those things.

[@Cloud-577]

no one explained recursion in so much detail like Kunal. Please someone give Kunal a medal already

[@poojabennabhaktula4883]

I dreaded recursion subset problem for almost an year now, and I stopped practicing because I was not very good with recursion. Now I can re-begin and work my way to FAANG

[@jamtaranumber2841]

me in the situation where i cant understand subset problems specially when for loop is used

[@sameerakhatoon9508]

@@jamtaranumber2841 you still struggling w/ iterative approach? lemme know, i can help you, can share the explanation here

[@jamtaranumber2841]

@@sameerakhatoon9508 yeah can you share your discord / linkedin

[@dubeyarts8661]

Sister are u in good company now?

[@arunny9430]

No one taught me recursion like you. I, like many others like me, initially thought I understood recursion completely after watching the Fibonacci and Factorial examples. But then the reality hit when I tried to solve some medium-level problems. I realized that my concepts are so hazy that I had no clue how to apply anything I learnt in logically writing code to solve a problem. This site not only taught me the concept, but it is also so thorough that it forced me see what is happening from different angles and write code in multiple ways. Thanks, Kunal, for making recursion as clear as algebra instead of it being some monster like vector calculus or something. You are so thorough. Awesome.

[@shanmukhasivasai8335]

First I found Difficulty in understanding the subset problem . After carefully going through I too got it .This guy is awesome

[@aakashprasad9777]

Brother you are legend Several videos I have seen but I never understood these concepts You made these thing so easy Thanks Brother for such a beautiful and lovely content Concepts are fully cleared With the help of these videos now I have the faith and confidence to crack good companies Thanks Brother once again Great going Keep it up and deliver content like these

[@KunalKushwaha]

Thank You 🙏

[@gouravsyal2052]

@@KunalKushwaha at 1:16:50 we should not sort the array as it will rearrange the array and subsets will be wrong. And we know in subset : 2, 1, 2 is the subset of 2, 1, 2 but 1, 2, 2 is not subset of 2, 1, 2

[@bijayMohanty12c5f]

​@@gouravsyal2052 yep bro

[@bijayMohanty12c5f]

2,1,2 is subset of 2,1,2

[@bijayMohanty12c5f]

​​​@@KunalKushwaha sir it change order of array 2,1,2 while sort it become 1,2,2 1,2,2 is not subset of (2,1,2 ) .(2,1,2) is subset of 2,1,2 1:16:08

[@bhavanamalapur5171]

I've been following your course for the past two months, and I just wanted to take a moment to thank you, Kunal. You're truly a coding legend! The way you break down complex problems and explain the solutions in such a simple, understandable way is genuinely amazing. Your teaching style is inspiring!

[@ARYANTIWARI-y5t]

These are the best videos on KZbin and still have less about of commends it's not good i guess public is so lazy . but in reality how much this person give the efforts to make these videos . i appreciate .. A BIG THANK YOU

[@armaanthakur8116]

Everytime you make me like your video no matter what I don't know anyone who explains every small things like you I love that you made this beautiful course for free even though it's so much worth. May krishna bless you !

[@shakibsiddiqui2999]

Bro when i see your video it gives me confidence 👍

[@singhsuryanshu]

Kunal, I cannot believe this is so easy. I wrapped my head around with backtracking a lot and was still confused. Even took sessions of a paid educational website to understand backtracking. And literally I just watched your video once and all concepts are clear. You are legend.

[@manavarora7644]

+1

[@rishika9102]

Hii can u please tell me that is this course worth following as m a beginner no programming background plz reply confused

[@rishika9102]

@@manavarora7644 Hii can u please tell me that is this course worth following as m a beginner no programming background plz reply m confused

[@Gookun]

@@rishika9102 PICK A programming language first, then learn it.

[@misbashaikh3357]

This video took me 8 hr to get completed but it all worth it. Thank you so much ❤

[@nizamkarivarsha1020]

I have seen so many videos related to java but no use after watching your videos Iam understanding concepts clearly Thankyou so much for helping those students who are not able to afford paid courses

[@iamyasirameer]

The man who invented the Recursion!

[@chaitanyaprasad6924]

Amazing!!!! You proved that a good teacher is not one who tells all the solutions but someone we can lead us to all solutions. As once I listen to you logic coding has become damn easy!!

[@aniketshetty6694]

Your confidence level is what makes you different from others. The best dsa course ever!

[@rockrk2519]

can anybody please tell in which video kunal has covered sliding window...

[@poorpanda9033]

@@rockrk2519 he hasn't covered yet he definitely will

[@anujar5508]

This is such a great video and it's incredible that you are not charging for sharing this immense knowledge. Just love the way you first explain the approach ,how to think and then actually solve the problem.Thankyou so much for these videos . And please please upload the graph and trees series 🙌

[@mathlover7688]

ye kya ho raha dsa se main bore kyon nhi ho raha ye toh magic ho gya kunal bhai ,love you bhai aisa best content ke liye ab lag raha main sikh jaunga dsa

[@charon71]

it is unbelievable how easy you can solve recursion tasks after watching these videos. You really get told HOW to think. Thanks alot!

[@KunalKushwaha]

So nice of you

[@whatwelearntoday]

This is the first time that i understood recursion in subsets after a lot of hunt for this material .Thanks a lot!

[@KunalKushwaha]

Glad to hear that!

[@Lifeoffacts21]

After all that your efforts and following all the previous playlist videos , Now i get some confidence in DSA to solve problems easily . Thanks Kunal bhaiyaa (Sir) for all that quality Content that i hunt for all over youtube

[@jamespeterson7824]

'Recursion made easy' by kunal. Good Intuation, Thought process and superb way of teaching. Good work 🙂

[@davidmwangi4312]

Best recursion series I have watched.Excellent explanation. Thanks Kunal

[@KunalKushwaha]

You are most welcome

[@arishkhan6300]

Brother you are legend i see the spirit in you to become s Minecraft stremer . You will achive great success as gamer.

[@beb57swatimohapatra21]

Finally!!! I understood these topics... you r a legend kunall

[@musicalboy2975]

Man you are freaking awesome. I feel confident on recursion and backtracing on watching your series .

[@pawanyadav4024]

amazing video, for learning subset and subsequence problems and solution orientation Thanks @KunalKhushwaha for creating such an amazing content

[@premraja55]

Legendary way of teaching! Thanks brother

[@KunalKushwaha]

My pleasure!

[@aakashyadav9117]

you are genius man , i did the subset problem of string "abc" and i used loop inside that , and you simple printed using recursion 🙌

[@nikitasrivastava1552]

I was facing the issue with the last code. Putting else statement as well (else {start=0}) when the condition for duplicates doesn't hold, fixed it. Brilliant explanation. Thank you

[@rakeshsagar9510]

I find his sub sequence tutorials much informative and communication is superb.

[@KM-rh8gd]

Bro i was starting up with my college and wanted to start with DSA glad that i have the right guide and tecaher.

[@Helly_Patel]

Thanks for teaching us like no one did till now!! One small request, please make lectures on dynamic programming as well!!

[@simranpreetkaur114]

In ques 9 we can just check if outer list contains that subset. If it doesn't contain, then only we should add it in outer. This way we'll avoid duplicates: public static List subsetDuplicates(int[] arr) { List outer = new ArrayList(); outer.add(new ArrayList()); for(int num: arr) { int n= outer.size(); for (int i = 0; i < n; i++) { List inner=new ArrayList(outer.get(i)); inner.add(num); if(!outer.contains(inner)) outer.add(inner); } } return outer; }

[@akashdeepgupta2085]

1:21:31 it will be good if we sort the array first, for the test cases like [1, 2,2,2] or [4, 4,4,1,4]. otherwise it will fail.

[@its_shivam_jha]

Great job man!

[@kcalbduorp3499]

.contains will take another internal nested loop so it increases the time complexity...

[@akashdeepgupta2085]

@@kcalbduorp3499 yes

[@prasadm3614]

Insanely simple explanation of subsets... M awestruck

[@omkarg01]

24:52 - 24:58 If I am not wrong, sliding window has not covered.

[@rakeshpotnuru]

Don't worry he keeps track of syllabus on github issue, maybe mistakenly said that.

[@faizanhaider3953]

phele to dur se pair chu k parNaam bro 🙏🙏 DhanSuuu lecture Kunal bhai... Nobody teaches like you.. but plz complete krdo bhai playlist... 🙏🙏

[@mohamedjasimazizg442]

I have been watching your videos for so long it's been very helpful to grow personally

[@varunkumar6223]

for the last question instead of adding the start or end index , if found duplicate just start the inner loop with outerarray size / 2 and it works fine #include using namespace std; vector subsetrec(string main,string pro){ vector s; if(main.empty()){ s.push_back(pro); return s; } char ch = main[0]; vector s1 = subsetrec(main.substr(1),pro); vector s2 = subsetrec(main.substr(1),pro+ch); s.insert(s.end(),s1.begin(),s1.end()); s.insert(s.end(),s2.begin(),s2.end()); return s; } void subsetitr(){ vector v{1,2,3,3}; vector res; res.push_back({ }); for(int i=0;i 0 && v[i] == v[i-1]) j= (n/2); // LOOK HERE for(;j

[@gnanaprakashm843]

Can you explain your thought process behind why it works ?

[@laxminarayanakoyyana1753]

@@gnanaprakashm843 he is just removing duplicates bro , that's it.

[@gnanaprakashm843]

@@laxminarayanakoyyana1753 I see I'll look into it. thanks 🙏

[@HARSHKUMAR-g2d6u]

Incredible course, the concept which you tell us in the starting of the recursion is enough to solve this problem and the track the answer in the function body is the awesome way to hold the answer more then the in the arguments

[@jatinkoli3389]

just started ur dsa course and fell in love with that

[@Nkchauhan-o9y]

I like the way you teach it is amazing that you are giving the tricks which person can apply to various types of questions. It's true even now i feal it is the best course for DSA out there on KZbin thanks for your valuable time and efforts for us. It would be so good if this was a whole course of DSA i would really like to learn whole DSA from you if it is feasible Please provide dynamic programing videos too! people would love it. Thanks for course and your efforts!

[@sadmansakibmugdho4134]

Hello Kunal. I want to know, After the DSA course, will you show us how to use our skills in open source and all that stuffs till how to approach in a company? If not then please consider this.🙏🙏🙏

[@DevanshuAugusty]

24:55 when did he teach sliding window?

[@bhavyabansal1143]

Thank you so much for explaining this beautifully. When can we expected videos for DP, graphs and trees?

[@kishanpareek2848]

Ye Kunal ka course bhot mast hai. Sab samaj aa gya

[@ombhandari6148]

Thank you brother Finally I understood how to solve the subsets problem.. Thanks a lot brother. You are doing great

[@KunalKushwaha]

More to come

[@arpithamjade386]

2:20 easy method static String rem1(String str,int start){ if (start>=str.length()) { return ""; } return str.charAt(start)=='a' ? rem1(str, start+1) : str.charAt(start) + rem1(str, ++start); }

[@yashkoolwal196]

One of most awaited vidoe

[@prashanthprashanth7570]

Broo tnq very much ❤❤❤ you are helping me a lot for learning recursion. since in these topic i am very confused.However i see your videos ❤ it's like a wow.

[@panchanansahoo1463]

Nice video kunal. For the last question we can add a check before adding the inner list to the outer list, If the outer list already contains the inner list or not

[@akashnag6459]

Easiest explanation of recursion in internet.

[@siddhigupta7673]

pls kunal complete the course no other course can match the level of content u were providing

[@29_jayavishnur89]

Fun fact: In iterating subsequence with duplicate you can set the start as outer.size() /2, thereby u dont need to use end variable itself

[@DSrikanthd]

This is just brilliant Brother, Keep doing it. Just waiting for the DP series, Please do it soon.

[@BrajBliss]

This and the merge sort video are the only one I just can't get in my head.

[@alonbrim]

Great Video! Very well explained! Great job Kunal, thank you very much!

[@KunalKushwaha]

You’re welcome

[@Fawzaan]

The Goat ❤

[@sriharshakandurivenkatases2587]

We are grateful to you for the knowledge you are providing for free🙏🙏 Waiting for your next DSA video #DSAWithKunal❤

[@atharvparlikar8765]

Waa ye hi time mila tha upload karne ko 😐

[@aasisinha6100]

Truely informative and lots of creativity in teaching...became friend without meeting you..

[@komalchauhan7535]

Great Video, Please complete this bootcamp asap.😇

[@karthick7983]

10:05 le kunal : ccd le siri : yeah bruhh!! LOL.

[@dsrfacts6483]

Amazing content bro... Keep doing the good work..Lots of luck 🎉

[@devesh819]

A new episode of recussion session 😂😂

[@Tomharry910]

Another great video. Thanks for the good work Kunal. Wish you the very best!

[@subhankarkanrar9494]

Just Enjoying every moment ❤. Love it😊

[@anuragbudakoti755]

Dhanyawad apka iss DSA course ke liye

[@vaibhavghatge8553]

Really awesome way of teaching finally, thinking in the recursive way, |2^n sub set

[@PrasunKundu]

Wait kar rha tha iske liye....

[@nishu0766]

please upload all the remaining topics of this DSA playlist as soon as possible

[@plutomessi21]

In this example, the recursiveSubstring method prints the current substring and then makes a recursive call with s.substring(1). Each recursive call creates a new substring starting from the second character of the previous substring. Output: vbnet Copy code Substring: abcdef Substring: bcdef Substring: cdef Substring: def Substring: ef Substring: f Empty String

[@andretheruler714]

recursion is still hard but you explained it well

[@abdulrauf7815]

The definition and recursion tree for subsets was very very great❤❤

[@apurwarokade3863]

You are a genius kunal 😊

[@samworld7923]

I thought to take half of outer list size as start index, but sooner realize what if multiple duplicate elements are coming, it will fail to survive that condition

[@mohammedadnan2449]

Q9 : Subsequences of a string with duplicate elements Can be solved in easier way with the code snippet mentioned below:- ------------------------------------------------------ List outerList = new ArrayList();//outerList outerList.add(new ArrayList()); for (int num : arr) { int size = outerList.size(); for (int i = 0; i < size; i++) { List internalList = new ArrayList(outerList.get(i)); internalList.add(num); if (!outerList.contains(internalList)) { outerList.add(internalList); } } } return outerList; ---------------------------------------------------------

[@Mlakshman-w9k]

contains method takes O(n) of time then it leads to O(n^3) for overall time complexity

[@Mlakshman-w9k]

static List subSetDuplicates(int[] nums) { Arrays.sort(nums); List outerList = new ArrayList(); outerList.add(new ArrayList()); for (int i = 0 ;i < nums.length ; i++) { int start = 0; int end = outerList.size(); if( i > 0 && nums[i] == nums[i - 1]){ start = start + (end - start ) / 2; } for (int j = start; j < end; j++) { ArrayList intenalList = new ArrayList(outerList.get(j)); intenalList.add(nums[i]); outerList.add(intenalList); } } return outerList; }

[@nagasatya5969]

Kunal, please try completing the series. It'd be of great help. cuz of all the videos I've watched on recursion, all of them were very specific to the prlms they taught and none of them explained how recursion actually works. I don't think they'd do any better with topics like dp. So, if you can, complete the series

[@rishabhrawat8197]

touched my heart as always

[@beyourself637]

00:03 String Questions and Subsequences 03:35 Recursion subset and subsequence concepts 10:19 Explanation of function call and process in string operations. 13:46 Recursion and string processing explained 21:02 Understanding recursion and string questions 24:31 Subset, subsequence, and string questions are important for interview preparation. 31:26 Understanding recursion and subset/sequence problems. 34:43 Recursion and string questions in a KZbin video 40:49 Discussion on various functions and activities using code 44:06 Recursion and string questions are challenging. 51:15 The video discusses creating subsequence and string questions. 54:30 Sequencing, string manipulation, and recursion in programming 1:01:07 Explaining recursion and its use in solving problems 1:04:05 Creating a new list based on the original list size. 1:10:16 Understanding subsets and complexities 1:13:16 Preventing duplicate elements in newly created subjects

[@harshjaiswal1634]

Recursion session... Just like therapy session

[@jatinkoli3389]

Bhaiya i am getting admsion into DTU CS can u please make a video 1st year roadmap I was waiting to get into college to start programming with ur course Loving ur confidence and content

[@devjoshi7062]

kzbin.info/aero/PLPX75d4curILdTmhcM5iJ6ReNx-LKW12P here, these are old videos of kunal when he used to work with a ed-tech, he has made a complete 4 year roadmap for B.Tech students

[@gauravdham9982]

Great work bro !! Keep it up and keep making such videos for others to learn!!

[@Nameiscantsay]

In the last question we can simply do that question as the previous question but after that just check whether each element is present in the list if it is there just remove duplicates from the list which takes O(N) time complexity. But brother you are sorting the array which takes O(NLog N) which is not effecient as compared to removing the duplicates after doing this question as the previous question.

[@muzi9786]

You are the best !!! please make some video about DP thanks ahead!!!

[@adityapalve3752]

very good video, i used to detest recursion kinda like it more than iteration now

[@dakubhai6014]

U r diamond dude...May lord protect u from Aliens for the boon of mankind.

[@aakashgoswami2356]

Other : How to solve a problem. Le kunal : How to approach a problem.

[@KunalKushwaha]

That was the plan

[@sameerakhatoon9508]

for qn 9, please find my recursive solution below approach: if we ignore the occuring of duplicates char means we ignore each of that duplicate char public class Recursion{ public static void main(String[] args) { System.out.println(subSetsWithDupInString("122", "")); } static ArrayList subSetsWithDupInString(String str, String ans){ if(str.isEmpty()){ ArrayList ls = new ArrayList(); ls.add(ans); return ls; } char ch = str.charAt(0); ArrayList left = new ArrayList(); ArrayList right = new ArrayList(); int i = 1; while(i

[@alpersener4269]

bro you're awesome thanks for the concepts you have taught us.👑👑👑

[@SAIFALI-rn5cs]

Bro, why I am getting error at p:p+ch, saying as Syntax error on token " : ", invalid AssignmentOperator.

[@sourabhsahu961]

Bhaiii you are legend, when you are coming with OOP java tutorials

[@ShubhamKumar-vu4ql]

44:21 can anyone explain the passing in the argument solution. i.e. how will u return two recursive calls simultansly, any help appreciated!

[@projectsdb4034]

Thanks for the great tutorial please continue the series

[@ragulp5489]

Thanks bro all the concepts u deliver is so clear sir. pls make some vdos on windows sliding, two pointer approach too sir.

[@SravanthiPotuluri-k5c]

Please make a video on subarray concepts

[@santoshis2568]

hi Kunal can you please do sliding window problems?

[@dmitriiserikov1528]

@Kunal Kushwaha , the solution in Q9 changes the order of the original array. Wouldn't the result be considered as a list of subsets and not a list of subsequences?

[@Mlakshman-w9k]

1:11:50 space complexity is O(2^n*n)

[@DevanshuAugusty]

Q8 C++ Solution : vector subsetIterate(vector vec){ vector ans = {{}}; for(auto i : vec) { int n = ans.size(); for(int j=0;j