The description should be more specific of what this kata asks for. Statements should be added such as:

The kata test cases have 100 random tests with arrays with between 80k-100k elements in them. A simple solution might take hours to finish the tests, but this kata requires them to be done in less than 12 seconds. The fastest solutions take around 10 seconds to finish.

Specfically explaining what the kata requires, rather than just calling it "a hard version" would allow users to make an informed decision on whether or not to attempt to solve it.

I use something faster than O(N^2) but it does not pass. How much time does your solution take to complete?