Hello,

I've got two issues. Timeout and random tests that fail.
Timeout is the fun part. Random tests is the strange part and i need some help.
If I believe the output of the attempt :

Input:
[3, 0, 0, 0, 0, 6, 0, 0, 0]
[4, 1, 0, 0, 0, 0, 7, 8, 5]
[7, 0, 0, 0, 0, 0, 0, 0, 0]
[9, 8, 0, 5, 4, 0, 0, 0, 0]
[0, 0, 0, 0, 0, 0, 0, 0, 0]
[0, 0, 0, 0, 8, 3, 0, 5, 4]
[0, 0, 0, 0, 0, 0, 0, 0, 2]
[8, 5, 1, 0, 0, 0, 0, 3, 7]
[0, 0, 0, 8, 0, 0, 0, 0, 9]
Value is not what was expected

My solution is wrong but I have no idea of the expected.

My solver found this solution :

[
  [ 3,9,8,7,5,6,4,2,1 ]
  [ 4,1,6,3,2,9,7,8,5 ]
  [ 7,2,5,4,1,8,9,6,3 ]
  [ 9,8,3,5,4,2,1,7,6 ]
  [ 5,4,2,6,7,1,3,9,8 ]
  [ 1,6,7,9,8,3,2,5,4 ]
  [ 6,7,9,1,3,5,8,4,2 ]
  [ 8,5,1,2,9,4,6,3,7 ]
  [ 2,3,4,8,6,7,5,1,9 ]
]

What should be the expected output ?

I do katas to propose them as a training for people. To avoid that they take unclear or unconstructive katas i must try them before.
I have the same complain than other people who complains :

• test missing
• no clear instruction
  ...
  Sad, the idea behind can be cool. But in this state, it's not a good kata. At least for me

Initially, yes I missed this part.
But after re-reading the description i notice that the order was wrong. Anyway I did not update my code cause the error was not relative.

After your comment, I made the good query and yes : it pass.

But this test is very confusing :

• should not use specific database functionality only ANSI (and no comments)

It fail if the request if not good event if the 3 conditions in the test description are good.

This Should be 3 tests :

• should not use specific database functionality
• should be only ANSI
• should not have comment

There should be some additionals tests :

• Should return row_number relative to the order
• Should be ordered by name

Thanks for your help. :)

I did not arrive to make it work with your explanation but after a quick look to your solution,
i made almost the same thing.
My concern was probably the stopping condition.

But i finish the exercice. How?

After for modification to my algorithm, i was able to get to the response of calc(10,16) and calc(11,16) (from the attempt) and I notice that i was exactly the same that the results i get with my pure math function except the last number that was not in the right base.
So i simply change into the right base the last number return by the fonction.

It solve the exercice but :

• the A092697 specify that's only for number < 10
• There's also this interesting link : https://en.wikipedia.org/wiki/Talk%3AParasitic_number#n_.3D_5

I am far from being good at math and I may have misunderstood some things in the links I have given but the results for n> 9 and n = 5 in base 10 may be wrong.

The exercise remains interesting. :)

Yes, this is the exemple written over wikipedia.
I base my first attempt on this algorithm with this exemple. It's work well for calc(4,10) and calc(4,16)

But now, let's try this algorithm with other number in base 10 : 2.
calc(2,10) should result 105263157894736842 (Verify thx oeis.org/A092697/list)

If you wrote the problem out starting at the right and worked left:

2
x2

4

This means that a number ending in 2 times 2 gives a product that ends in 4, so 4 is the next digit to the left of 2.
We also figured out that we have to deal with a 0 carry.

So in the number on the top, write a 4 with the 0 carry over the top to create the next iteration for the multiplication:

0
42
x2

84

So now we know the digit to the left of the 4 in the multiplicand is 4, with a 8 carry.

80
42
x2

84 <-- almost same answer - the only difference is in the carries.

And If i continue i have an infinite loop.

So where's the fail? :x

Don't know if i will be happy or if i will be sad thinking about the time spent on this simple exercise...
I now got a solution in full math that seem to work. My first attempt manipulated strings...

But !
Some tests always fail (22 tests pass/28).
The 6 faillings test are the 6 in base 16 where n >= 10.
For exemple : calc(10, 16) return me "1019c2d14ee410" which is "1019c2d14ee4" + "10"

EDIT : In fact, i implemented https://oeis.org/A092697 so it logicaly fail.
Does i should implement https://oeis.org/A128857 instead?

Is it possible to know the result of calc(10, 16) ?

EDIT : Forget this comment. In fact my algorithm seem to be completly wrong.

I got a solution that make pass the 'run exemples' and also the exemple i found over wikipedia.
However, it fail on the attempt (Some fail and one forever loop). I can't figure out why.

Is it possible to add more exemple (with other base & value) or a least for most of the tests that fail when submitting, give the expected?