You'll see all solutions when you upload your own.

haha lol, its just that when seeing "There is no solution to show" pop up, I thought you had already given up on this kata.

Hi man. I did it already ) Let me know if you need a help with theory. Cheers.

two years late, but you and I had the exact same issue. there is a way to solve it though; think of how you would solve this on a square grid, and notice what the algorithm behind it actually does to each individual piece.

my first 1kyu kata solved! this was an amazing kata, spent damn near 2 weeks on this, but it was really worth it. thank you, jaybruce, for making this; that's 83 people very satisfied with this kata now :)

oh wait, I've figured it out!

the test cases sort a list of PokerHand classes, and you need to sort them based on the hand value.

ah crap, I actually don't understand it too; I pass example test cases but the random test cases just say "failed at test n".

I'm confused, what?

failed at test 0: [JH AH TH KH QH, JH 9H TH KH QH, 5C 6C 3C 7C 4C, 2D 6D 3D 4D 5D, 2C 3C AC 4C 5C, AS AC AH KS AS, JC 7H JS JD JH, JC 6H JS JD JH,
KH KC 3S 3H 3D, 2H 2C 3S 3H 3D, 3D 2H 3H 2C 2D, JH 8H AH KH QH, 3S 8S 9S 5S KS, 4C 5C 9C 8C KC, 8C 9C 5C 3C TC, QC KH TS JS AH, JS QS 9H TS KH, 
6S 8S 7S 5H 9H, 3C 5C 4C 2C 6H, 2C 3H AS 4S 5H, AC KH QH AH AS, 7C 7S KH 2H 7H, 7C 7S 3S 7H 5S, 6C 6S 3S 6H 5S, 3C KH 5D 5S KC, 5S 5D 2C KH KC, 
3H 4C 4H 3S 2H, AH 8S AH KC JH, KD 4S KD 3H 8S, KC 4H KS 2H 8D, QH 8H KD JH 8S, 8C 4S KH JS 4D, KS 8D 4D 9S 4S, KD 6S 9D TH AD, TS KS 5S 9S AC, 
JH 8S TH AH QH, TC 8C 2S JH 6C, 2D 6D 9D TH 7D, 9D 8H 2C 6S 7H, 4S 3H 2C 7S 5H] 

should equal [JH AH TH KH QH, JH 9H TH KH QH, 5C 6C 3C 7C 4C, 2D 6D 3D 4D 5D, 2C 3C AC 4C 5C, AS AC AH KS AS, JC 7H JS JD JH, JC 6H JS JD JH, 
KH KC 3S 3H 3D, 2H 2C 3S 3H 3D, 3D 2H 3H 2C 2D, JH 8H AH KH QH, 4C 5C 9C 8C KC, 3S 8S 9S 5S KS, 8C 9C 5C 3C TC, QC KH TS JS AH, JS QS 9H TS KH, 
6S 8S 7S 5H 9H, 3C 5C 4C 2C 6H, 2C 3H AS 4S 5H, AC KH QH AH AS, 7C 7S KH 2H 7H, 7C 7S 3S 7H 5S, 6C 6S 3S 6H 5S, 3C KH 5D 5S KC, 5S 5D 2C KH KC, 
3H 4C 4H 3S 2H, AH 8S AH KC JH, KD 4S KD 3H 8S, KC 4H KS 2H 8D, QH 8H KD JH 8S, 8C 4S KH JS 4D, KS 8D 4D 9S 4S, KD 6S 9D TH AD, TS KS 5S 9S AC, 
JH 8S TH AH QH, TC 8C 2S JH 6C, 2D 6D 9D TH 7D, 9D 8H 2C 6S 7H, 4S 3H 2C 7S 5H]

You can avoid a copy with a simple syntax making it quite similar to using a unique pointer in C (cf this kumite not to spoil others in comments)

oh shit, my bad, I forgot to add it

how about adding the spoiler tag, djeezes

I must say, that was quite a bit harder than i expected it to be. Really fun to solve though!

It might be worth adding to the description a reference to "Difference of Squares".