I will have to keep that in mind. Thank you.

Hi All. I am certain that my iterative solution works as all tests pass except for extremely large numbers i.e. 10billion and 1. Please help reduce the test cases to reasonable size integers. I cannot imagine being able to iterate over such a large number in real world applications. Especially if my solution tends to O(n^2) and O(n^3). It is just impossible to win here. I presently receive a "MemoryError", all possible solutions seem not to apply except refactoring the code to reduce memory usage e.g. through creation of new objects and the like. Otherwise, I am a sitting duck. Will appreciate any help for one and all.

Technically, it is not, but the longest palindrome substring within that string is a string of length 1. In that case, any random letter in the original string is considered a palindrome on it's own.

So, after hours of debugging my solution, I found that the instructions were pretty misleading. How you instruct us to treat negative numbers is not how you designed the final test cases. Did you use two's complement (caught on from the discussion here), if so please update the instructions?