Knights Tour - Solution | Recursion | Data Structures and Algorithms in JAVA

[@pratyush__agarwal]

Very well explained. N queen question was the foundation stone of this question. The way you sequence all of the question is also very important and you are ace on it.❤️

[@Pepcoding]

Keep learning and keep loving Pepcoding😊

[@snehaashishgupta1254]

istg am able to register recursion only because of the ordering of recursion questions!

[@pallavimeshram5491]

Finally I can say that I know recursion, Thank you so much for making this videos, I got stucked in recursion in past that's why I was not able to proceed with topics like dp, trees, graphs. But I am feeling confident now.

[@AbhishekChaudhary-hl9kx]

OMG, done from itself same approach after the dry run and recursion tree. thankyou very very much sir.

[@pratyushtiwari103]

I was fearing from recursion but after watching your videos i'd say just one thing- maja aagya. Thank you sir for such an awesome playlist

[@Pepcoding]

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 review us here - g.page/Pepcoding/review?rc

[@KejriwalBhakt]

Abb yeh maza sabko do..

[@ShreyasShirwadkar]

Sir thank you for this recursion playlist. I was a complete beginner but now I have my basics cleared and can solve diff questions too! THANK YOU 🙏

[@priyanshshukla5777]

Binge watching DSA season 1 (Foundation course ) Thank You Sir

[@a_85_viveksinghyadav60]

Sir today I completed this series and I tried one question of subset using recursion , can't tell you how I feel after solving that by myself. Thanks a lot sir for this amazing series of recursion.

[@yelp9359]

Phli baar itna maza aa raha hai sir recursion padhne me. 🤩🤩

[@Pepcoding]

Thank you. Please support by subscribing and pressing the bell notification. Also, it will be really helpful to share this in the college groups.

[@yelp9359]

@@Pepcoding already done sir ☺️

[@gauravgupta9477]

Yeah....Now i intentionally write every possible code i could think of recursively. Maza to aa raha hai bhai.

[@aashishgoyal1436]

Thank u so much sir. completed recursion playlist today. Really fantastic videos and explanations.

[@Pepcoding]

Wow. bhot badhiya. ab aage badhie, DP pe

[@aashishgoyal1436]

@@Pepcoding sure Sir. Thanks a lot for ur guidance

[@mayankverma714]

Completed the Recursion in Backtracking ; Moving to DP. Thanks to sumeet sir.

[@karlmaximum500]

Sir thank you for this. You are our savior in these uncertain times. Also when will you upload DSA and interview prep videos on KZbin?

[@Pepcoding]

Bass next month

[@karlmaximum500]

@@Pepcoding Thank you so much.

[@ShivamSinghMAITCSE]

@@Pepcoding sir singh in usa me kitta accha video banwaya sir aapne 😍😍

[@potato-gi1xr]

thank you so much sir for this Playlist. initially didn't wanted to watch basic recursion videos, since I already knew about them. But, I watched which made my concepts really good and solved the questions on NADOS. Now, I have solved all the questions in DSA level 1- Recursion and backtracking. thank you so much sir.🙏🙏🙏

[@democratcobra]

Recursion was nightmare to me ...now i am loving it ..thank you Sumit sir...

[@amanwadhwa5432]

Now i am also confident about recursion Thanks sir

[@bitqahdi6592]

I enjoyed the entire playlist ! Thanks my best friend

[@Pepcoding]

I am glad you liked it. I also hope that you are watching till end and trying to understand the what, how and especially why of the problem. Keep learning and keep loving Pepcoding☺️

[@bitqahdi6592]

@@Pepcoding Sure Pepcoding is

[@swatimaurya9405]

thank you so much sir itne helpful content ka lea ajj recursion apki vejha se bhut ache se aya ha samjh.😊

[@Pepcoding]

Glad it helped, for better experience, doubt support, career opportunities and well-organised content, visit - nados.pepcoding.com Don't forget to follow us on Instagram instagram.com/pepcoding/

[@AnujRYadav]

Completed This Playlist 💗 Feeling Confident Thank You sir

[@Pepcoding]

Very good, keep it up and always feel confident beta.

[@AnujRYadav]

@@Pepcoding Thank You So Much Sir

[@abhisheksoti1115]

I express my sincere gratitude towards you Sumeet Sir. I know I could not attend regular classes since I am a 7 year experienced developer in the industry, but still wanted to say Thank you for teaching me so much. I would keep on learning, targeting to finish DSA level 1 this month, Kudos to Nados, great platform.

[@Pepcoding]

We are really glad that it was helpful for you. Stay tuned on NADOS and on our Instagram account.

[@ParasVashishth_RV]

Sir, recursion ke liye es playlist ke concepts enough h na, bcz ye vale last 10 ques. khud ban gaye the. plz reply

[@Pepcoding]

Enough to nh but basic idea de dege ye questions apko recursion ka baki abhi level-2 main bhi cover krege aur questions recursions k

[@ParasVashishth_RV]

@@Pepcoding ok sir Thanx

[@mickyman753]

@@Pepcoding sir iske baad seedhe level 2 ka recursion chalu krdu kya ,mujhe basics atey hai dsa ke but sirf recursion aur advance ds main hi problem hai

[@raj_kundalia]

Watched on 29 December, 2021, thanks for the video.

[@ashwinnema06]

Nice explanation sir. I solved this question myself but I was not getting right answer. Then I saw your code in the video and I found that I missed one condition. Now I solved this question.

[@Pepcoding]

Great! For better experience and well organised content sign up on nados.io And for being updated follow us on Instagram instagram.com/pepcoding/

[@nitinnegi862]

Thank you sir for this awesome series!!

[@ShivamSinghMAITCSE]

sir singh in usa me kitta accha video banwaya sir aapne 😍😍

[@Pepcoding]

[@anshshrivastava9107]

1:53 laaiye isko hum koshish karne ki koshish krte hain... XD real life recursion

[@mickyman753]

hands down the playlist to understand recursion

[@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 )

[@codeblooded6760]

Shouldnt it be chess[0].length for column instead of chess.length ?

[@Pepcoding]

Beta, both will work because n*n size h

[@venkateshkalyan9429]

Sir , why didnt you mention any where in the video that , its a back tracking Algo ? am I missing something ?

[@vanshdhiman366]

Really great😁 kya samjhate ho sir SIR FLATTENING A LINKED LIST PRR EK VIDEO BANADO, SAMAJ NHI AA RHA

[@Pepcoding]

Thank you beta. Pkka bnegi video.

[@sharuk3545]

woww you convet the hard problem in the easy problem

[@Pepcoding]

Thankyou beta! I am glad you liked it. I also hope that you are watching till the end and trying to understand the what, how, and especially why of the problem. If you like our efforts, will you like to review us here - g.page/Pepcoding/review?rc

[@harshitkaushik4144]

Always there for your support sir.

[@Pepcoding]

Thanks Man😍🙏🏼 Much appreciated😘

[@ShivamSinghMAITCSE]

Sir please ek aur playlist jisme wo success stories wale baache apna question discuss krte hai unke solution wale video ko us new playlist me add kr dijiye sir " interview previous asked questions "

[@Pepcoding]

yar, kar to denge. par companies ka non-disclosure agreement hota hai apne staff ke sath. to bache discourage karte hain ajkal. So we will make a list and do a mock interview including those questions.

[@pranshulkharniwal8146]

@@Pepcoding sir list ban gai kya??

[@SugamMaheshwari]

Sir , Why doesn't it give answer when we don't follow the clockwise pattern of moves ?????

[@Pepcoding]

beta code wo bhi sahi hoga. Par online judge jo hai wo to text check kar sakta hai. Uske liye ek order lena jaruri tha. Maine clockwise le liya

[@ShivamSinghMAITCSE]

Bhai aapka answer jo hai wo ek expected answer ke saath seedha seedha check hota hai agar usme ek space ka bhi difference hoga toh wo wrong code bata dega . Its as simple as that pr code wo bhi sahi hai aapka

[@prateek2159]

Sir this solution results in time limit exceeded on naados, gfg and codechef's compilers. Please look into it. And sir you didn't explain warnsdorff's algorithm for this question.

[@Pepcoding]

Thankyou for the feedback. will look into it and for better experience and well curated content visit nados.io

[@nknidhi321]

Thank you so much..🔥🔥

[@vikasjoshi7236]

sir ye video graph ki playlist m kyu h ?

[@AryanSharma-dh4fb]

warnsdorff's algorithm ki wajah se shadad, but you will have to google that algorith.

[@vivekkumar-ct7rb]

Sir please reply karna, Pehle time complexity karoo ya dp and greedy kyuki pepcoding ke site jab click karta hu to donno har baar change ho jataaa hai, matlab kabhi time complexity ooper aata hai to kabhi DP.

[@tusharchamp488]

Sir SOlution Submit nahi ho rha ye wala IDE par kya kre...???

[@vrindasharma4035]

Finally, completed the recursion...... So, happyyyyyyyyyyyyy!!!!!!!!

[@kashba]

abhi kitna karliya aapne?

[@jyotiprasadchatterjee8707]

can i learn these from pep code from class 10? im intersted a lot in computer

[@himanshuchhikara4918]

thankyou sir for making videos like this

[@Pepcoding]

Thank you very much!! share as much as you can

[@sairajdas6692]

Sir I think we should also check if (chess[r][c] != 0) after first if. May be that's why it is not accepting for some test cases.

[@deepakagrawal7687]

it will not enter into block where displayboard is called for 5*5 matrix. please tell the input for which it will enter the if condition. also please tell why for 5*5 or your input as well blank is output

[@HarshKumar-nh6be]

Great teaching❤

[@Pepcoding]

Glad it was helpful!

[@035asadali8]

i just realise i complete the playlist and learn all basics of recursion and backtracking in playlist

[@csgirl6895]

clean and easy code. Thank you so much sir

[@Pepcoding]

Glad it helped

[@navaneethakrishnak9384]

hello sir actually here the order of writinf recusrsion function maters but why?like if we write 30th line on 31 and 31st on 30 we are getting error

[@ManishTiwari-ge1wc]

Great Explanation

[@Pepcoding]

Thankyou beta, I am glad you liked it. I also hope that you are watching till end. If you like our efforts, will you like to write a few words about us here - (www.quora.com/Which-is-the-best-institute-for-coding-in-Delhi)

[@harshitkaushik4144]

manneeessshhhh bhaiiiiii

[@sriramkrishnamurthy4473]

Bhai from which video is backtracking actually started in this playlist apart from level 2 level 1 ke playlist me kaunse video se backtracking start hota hai ?

[@NituPandelPCECS]

Thank you So much🙇

[@peeyushpachaori4626]

Thanks for putting it through, it's great to watch and learn :). For the Knights tour problem, it seems an extension of the Hamiltonian problem, however, I noticed that the code doesn't check for already visited cells. Is it something not required for this?

[@Pepcoding]

Yes, it is hamiltonian only. Visited nahi chaie kyunki chess board mei he daal dia value, jisse pta chal jata hai ki cell visited hai. If you like my efforts, I request a review g.page/Pepcoding/review?rc

[@rahulranjan7567]

Visited check ho rahi hai base case mein...chess[i][j]>0 hogi to return ho rahi that means we are not going urther down the call. agar hum yeh check nahi karenge toh vauge values aayenge in cells

[@AmanKumar-jt9zb]

Thankyou so much for your solution videos sir i have missed the actual line of this code that leads to backtracking and it lies in the base case i was setting the last position but while returning i was not setting it to 0 again just in the base case and because of that i was getting wrong answer but now i know what mistake i have dont just because of your solution video. Thankyou again.

[@Pepcoding]

Glad to know that you liked the content and thank you for appreciating. The love and respect which I get from you people keep me highly motivated and the same I am able to forward It to you people through my videos. So, keep motivating, keep learning and keep loving Pepcoding😊

[@dheerajkhushalani2619]

can i display on moves greater than 25 condition.. it can be more easy to understand?? if move >25{ display(chess) return; }

[@letsdoeverythinginoneweek9398]

sir jaise ki hamna display kardiya apna board ko toh usa hatana jaruri ha kya matlab display toh kar diya hamna apna output

[@parthsaraswat9744]

Sir yaha recursion ke basics complete hue hai..backtracking ke thode level question ki videos dekhe ya fir DP par aa jae

[@abhinavkohli4293]

pecoding's online judge is not working

[@nivealokhande2153]

bnd kr dia hai 😢

[@sakshiaggarwal6199]

Thank You so much sir!!

[@hemantsingh-zo3iw]

Sir, you are awesome

[@Pepcoding]

So nice of you

[@nikhilkumarjamwal5322]

Good one.👍 I did not get that last part of else if condition. Can someone tell me why did we use that condition and how our knight came to last position of table???

[@kashba]

n queens aur flood fill dekho questions pehle ye smajh aajayega

[@loserfruit9663]

Feel aa gayi sirr

[@neerajyadav9412]

sir ab DP kre yaa Time and Space complexity

[@K_EC_piyushkumarsingh]

Is it necessary to make chess[][]=0 in base case.?

[@Pepcoding]

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

[@loserfruit9663]

Dhanyawad

[@sahilgupta9378]

whats the time complexity????

[@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.

[@sahilgupta9378]

@@Pepcoding thanks sir, for sure:)

[@sahilgupta9378]

@@Pepcoding Thankyou sir, I posted in telegram and in a minute someone helped, great community

[@ritikshrivastava9442]

what is the time complexity of this man?

[@dark_techyy]

Ye undo.wali bat smj me ni ayi...hme ek bar visit kiye hue cell ko Dobara visit nhi krna h na...to unvisit q krre h last me?🤔🤔🤔

[@jigarlove2113]

because hme sare answers chahiye n. jitna bhi possible ho sakta hai

[@divyanshbarar3840]

again best ..................... :,*

[@rishabhgoyal2835]

this is showing in graphs of level 1 , plz update it

[@Pepcoding]

Ok ji.

[@taruvarmittal1484]

sir, aapne move reset kyu kiya ? I mean saari calls ke baad chess[row][column] = 0 kyu kardiya vaapis ?

[@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.

[@taruvarmittal1484]

@@Pepcoding ok thankyou sir

[@Otmar_Schloetterlein]

i have found this way and the best we can go from field 64 to field 1 so are this a solution for all fields

[@Otmar_Schloetterlein]

Lösung zum Rösselsprungproblem aus dem Schach von jedem beliebigen Anfangsfeld 11 24 47 34 01 14 49 36 46 33 12 25 48 35 02 15 23 10 45 64 13 26 37 50 44 57 32 29 60 63 16 03 09 22 61 58 27 30 51 38 56 43 28 31 62 59 04 17 21 08 41 54 19 06 39 52 42 55 20 07 40 53 18 05

[@omda6197]

sir gfg aur leetcode kaise use kaRe aapki videos k saath-2

[@kiyotaka721]

sir is there any way instead of writing 8 recursive call we write the call in a for loop?

[@Pepcoding]

this is more convenient. yes there is a way. using two d arrays.

[@kiyotaka721]

@@Pepcoding ok sir and thank u for this amazing content

[@rahulranjan7567]

Gruji is there a position on chess board jisse knights travel krr le puri board ko? I want to see the output for a successful case.Thanks guruji

[@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.

[@sudhindrashenoy7992]

Hello Sir.. I kindly request you to create videos on sliding window and two pointers coding patterns

[@Pepcoding]

Hanji beta, ek bari jo agenda main questions h vo complete kr le, then ye sb cheeze bhi cover kr lenge

[@harshpandey7605]

Sir chess length*chesslength ke liye alg se conition kyun likhi hai please bata dijiye

[@Pepcoding]

u have to fill the board with each move of the knight and in order to stop the recursion we should know how many total boxes are to filled so as total number of boxes in 2-d matrix is defined as n*m so base case would be applied on that chess length*chess length

[@harshpandey7605]

@@Pepcoding Thank you very much

[@vaibhavagarwal9055]

solution is wrong. not working

[@arijitgoswami7570]

Sir sare move chalne ke bad chess[r][c]=0 kyu krre ho wo samajh me nhi aya..

[@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.

[@rohitmeena1772]

bhai saare moves ko level 1 maan, isme apne backtrack karte hue humne saare options explore kar liye hai isliye ab wapas initial value set karna padega na. Ek baar dry run karke dekho paper me.

[@venkateshvenky2880]

Thanks sir...♥️

[@Pepcoding]

Most welcome

[@arshadmanxoori07]

Sir Recursion ke baad.. DP karuu ya Basic DS?

[@yashodeepdhas8408]

Same doubt bhai

[@arshadmanxoori07]

@@yashodeepdhas8408 vroo i think DP krna hi sahi rhega

[@nivealokhande2153]

@@arshadmanxoori07 bhai basic phle krna hota hai, fir recursion, fir dp

[@arshadmanxoori07]

@@nivealokhande2153 2 saal ho gye bhai.. ab to sb kr liya

[@nivealokhande2153]

@@arshadmanxoori07 shi hai😂, mai hi late aaya idhr lgta hai

[@SCRIPTSAG]

Sir aapke sare question samgh aa ja rhe hai but sir aap standard formate me return ker diya kre values ko en Sare problma beacuse on geeks of geeks and leetcode we faced many problems

[@Pepcoding]

ok ji

[@AshishGusain17]

thanks

[@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/

[@JohnWick-kh7ow]

Sir aise video ab kyo nhi banate. ab adhe ghante ke video hote h maja nhi aata. Videos short banaya karo achha response milega.

[@whynesspower]

3:54 "Tu mujhe marwayegi" ended up being true, faced the same question in microsoft interview HAHAHA

[@nknidhi321]

🔥❤️

[@dayamalik6025]

Hello chachu your Aryan

[@Pepcoding]

i love you aryan

[@sasikalaramesh8751]

please explain in english..:(

[@anjneykumarsingh4461]

Isko dry krne m mja ayega

[@Pepcoding]

Padhte rahie

[@anjneykumarsingh4461]

Ji guruji

[@pratikjha2742]

knight is ghoda

[@Pepcoding]

Thank you so much 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 )

[@nivealokhande2153]

@@abacas2175 😂😂

[@smitjoshi4513]

Can anyone tell me what's wrong in the following code, as I am getting a blank output. import java.io.*; import java.util.*; public class Main { public static void main(String[] args) throws Exception { Scanner scn = new Scanner(System.in); int n = scn.nextInt(); int[][] chess = new int[n][n]; int row = scn.nextInt(); int col = scn.nextInt(); printKnightsTour(chess,row,col,0); } public static void printKnightsTour(int[][] chess, int row, int col, int upcomingMove) { if(row=chess.length||chess[row][col] >0){ return; } if(upcomingMove == chess.length * chess.length){ chess[row][col] = upcomingMove; displayBoard(chess); chess[row][col] = 0; return; } chess[row][col] = upcomingMove; printKnightsTour(chess,row-2,col+1,upcomingMove+1); printKnightsTour(chess,row-1,col+2,upcomingMove+1); printKnightsTour(chess,row+1,col+2,upcomingMove+1); printKnightsTour(chess,row+2,col+1,upcomingMove+1); printKnightsTour(chess,row+2,col-1,upcomingMove+1); printKnightsTour(chess,row+1,col-2,upcomingMove+1); printKnightsTour(chess,row-1,col-2,upcomingMove+1); printKnightsTour(chess,row-2,col-1,upcomingMove+1); chess[row][col] = 0; } public static void displayBoard(int[][] chess){ for(int i = 0; i < chess.length; i++){ for(int j = 0; j < chess[0].length; j++){ System.out.print(chess[i][j] + " "); } System.out.println(); } System.out.println(); } }

[@hodex5763]

in the main function when you call printKnightsTour you have to pass the move as 1, since you are passing 0 there all the moves in the matrix even when visited by the knight get decremented by one so it never reaches the bas case where it has to execute the displayBoard function. So your code doesn't print anything, if you want to stick to your code in the base case you can write, if(upcomingMove + 1 == chess.length * chess.length)

[@TechyEra]

@@hodex5763 I converted that code in php, it's working great. But my own code going into infinite loop. To me both codes are the same. working code: function printKnightsTour(&$chess, $row, $col, $upcomingMove) { if ($row < 0 || $col < 0 || $row >= count($chess) || $col >= count($chess) || $chess[$row][$col] != ".") { return; } if ($upcomingMove == ( (count($chess) * count($chess))-1 )) { $chess[$row][$col] = $upcomingMove; displayBoard($chess); exit(); } $chess[$row][$col] = $upcomingMove; printKnightsTour($chess, $row - 2, $col + 1, $upcomingMove + 1); printKnightsTour($chess, $row - 1, $col + 2, $upcomingMove + 1); printKnightsTour($chess, $row + 1, $col + 2, $upcomingMove + 1); printKnightsTour($chess, $row + 2, $col + 1, $upcomingMove + 1); printKnightsTour($chess, $row + 2, $col - 1, $upcomingMove + 1); printKnightsTour($chess, $row + 1, $col - 2, $upcomingMove + 1); printKnightsTour($chess, $row - 1, $col - 2, $upcomingMove + 1); printKnightsTour($chess, $row - 2, $col - 1, $upcomingMove + 1); $chess[$row][$col] = "."; } not working code function printKnightsTourNotWorking(&$chess, $row, $col, $upcomingMove) { // if ($row < 0 || $col < 0 || $row >= count($chess) || $col >= count($chess) || $chess[$row][$col] != ".") { // return; // } if ($upcomingMove == ( (count($chess) * count($chess))-1 )) { $chess[$row][$col] = $upcomingMove; displayBoard($chess); exit(); $chess[$row][$col] = 0; return; } $chess[$row][$col] = $upcomingMove; $directions = [[2,1],[2,-1],[1,-2],[-1,-2],[1,2],[-1,2],[-2,-1],[-2,1]]; for($k=0; $k= count($chess) || $dj >= count($chess) || $chess[$di][$dj] != ".") { continue; } else{ printKnightsTour($chess, $di, $dj, $upcomingMove + 1); } } // printKnightsTour($chess, $row - 2, $col + 1, $upcomingMove + 1); // printKnightsTour($chess, $row - 1, $col + 2, $upcomingMove + 1); // printKnightsTour($chess, $row + 1, $col + 2, $upcomingMove + 1); // printKnightsTour($chess, $row + 2, $col + 1, $upcomingMove + 1); // printKnightsTour($chess, $row + 2, $col - 1, $upcomingMove + 1); // printKnightsTour($chess, $row + 1, $col - 2, $upcomingMove + 1); // printKnightsTour($chess, $row - 1, $col - 2, $upcomingMove + 1); // printKnightsTour($chess, $row - 2, $col - 1, $upcomingMove + 1); $chess[$row][$col] = "."; }