CHALLENGE: Write a function that gets an array of dominoes as input and outputs the length of the longest domino-sequence!

Question

EXAMPLE 1:
- input: [[1,2],[4,5],[9,6],[2,3],[5,8]]
- output: 2 ([1,2]-[2,3] OR [4,5]-[5,8])

EXAMPLE 2:
- input: [[7,8],[1,2],[8,4],[2,3],[1,0]]
- output: 3 ([0,1]-[1,2]-[2,3])

INFO: Rotating pieces is possible!

WINNER WILL BE NOMINATED TOMORROW NIGHT!

GOOD LUCK AND HAVE FUN :)

Answer 1

https://code.sololearn.com/cfLeDq0kbS16/?ref=app

My python solution. Probably not the fastest, but I think it works. Thanks for the challenge!

Answer 2

Do not spam in existing threads to advertise your own thread. Please remove all the posts that you have made within 24 hours. If you do not comply, there is a risk that your profile will be blocked.

Kindly take note. Thank you.

Answer 3

Don't advertise your thread in other posts (1 or 2 is ok but you've gone full fledged). Please delete those posts, or you will risk being reported.

Answer 4

TIME IS UP CODERS... ONLY 1 PERSON WAS ABLE TO SOLVE THE PROBLEM. SO NO NEED OF NOMINATING ANYBODY !
MAYBEE THIS ONE WAS A LITTLE TO HARD ...

TRY THE NEXT ONE!!!
https://www.sololearn.com/Discuss/569992/daily-challenge-write-a-code-that-get-as-input-a-mathematical-function-as-string-calculate-and-print

(ps: my domino-code will be uploaded tommorow)

Answer 5

Yeah advwrtisement is illegal in sololearn let people get attracted.

Answer 6

@Pixie
@/*S Vengat*/
@Janhangeer
@hatsi rey

I'm NOT trying to advertise anything or anybody.
Actually, I just felt in love with those challenges, like others did too! The reason why I've posted it a few times is, that I want EVERBODY to be able to educate them selfs in a playful way.

And therefore I would recommend to start a seperate section for code challenges/competitions. The idea of people posting smaller challenges for other people is brilliant, because this will improve ALL our SKILLS!

ps: don't block me !!!

Answer 7

@André Oliveira
yes code will be uploaded tonight!

btw: we had to solve this problem in university homeworks one day. I've got more of them... and will let you try them all (if you dare) :D

Answer 8

@Ready: Your algorithm only seems to work for increasing sequences of domino tiles. If your input consists of multiple copies of the piece [0-1] it would fail.

My ad hoc, but admittedly very inefficient, solution would look something like this:
- Turn the input into a graph: Every domino tile is a pair of nodes connected by an edge and there is an edge between nodes of different tiles iff the corresponding sides of the tile have the same number.
- Use dynamic programming to solve the Longest Path Problem on this graph.

I'm not going to implement this, because I don't have the time now, but maybe this helps someone.

Answer 9

Don't advetise your challenge in other threads please

Answer 10

I think it should be [0,1] in example 2 instead of [1,0].

Answer 11

It looks hard eheh :) I will give it a try! Have you done it yet?

Answer 12

@Ready result should be a single line of chain.
but for calculating the longest you can use the more linked to a single domino idea ;)

Answer 13

looking in this past days challenge.
hey, Julian report yourself for spam you :)

ps:where is your dominoes code?

Answer 14

sorry, i don't understand the challenge

Answer 15

@Lakshay
Don't forget dominos can be flipped. so the 1,0 can become 0,1

Answer 16

@julian any other challenge

Answer 17

my hint: to prevent the problem of copies you could easily write a class (eg: Element) containing the touple and then you can check if a certain Element is already used (by comparing the refernece to the Element instead of the touples it self)

Answer 18

@Tobi
Your suggestion is totally right. converting it to a bellman-ford like (graph) alogorithm would solve the problem efficiently (but that's to hard for beginners)!!!

Answer 19

HEY PEOPLE OUT THERE. I'M BACK FROM VACATION.
AND ANOTHER DAY MEANS ANOTHER CHALLENGE. CHECK IT OUT!!!

https://www.sololearn.com/discuss/622449/?ref=app

SOLUTION WILL BE UPLOADED TOMORROW NIGHT!

Answer 20

NEW DAILY PRINT-CHALLENGE:
https://www.sololearn.com/discuss/628136/?ref=app