lol

try printing your inputs for the fixed and random tests.

I pass when I run the sample tests, but when I hit attempt I get an indexError which makes no sense. It works fine when I run it in Pycharm with the array that gave me an indexError here. My code also produces correct results when I run all of the tests found in the instructions in Pycharm.

Interesting Kata. Thank u dude.

The set class doesn't support operator[]. It's contents aren't stored in a linear data structure, it's some sort of tree or hash table. So even if [] were supported, the underlying logic will still be linear run-time. The iterator allows me to access the elements in order of insertion. So by inserting in a strictly ascending fashion, I can recover that order with an iteration loop. If you want to see an array based approach, check out g964's solution. It's probably better than mine. My C solution is also array based, but it's not dynamic. I guesstimate the maximum value of n.

why don't u just return u[n] at last ? It may remove the last loop I think.

wow, yet you are the another who uses exception I've seen. Huhhhhh

return the longest substring(which is palindrome)'s length... It's really confuse

So celver your solution is!