Ocean's Anti-11

ID: anti11

Difficulty: 3.2

CPU Time: 1 second

Memory: 1024 MB

Solution

It might be a bit tricky to notice the pattern, but the number of eligible strings is actually the Fibonacci sequence, though the length n actually corresponds to the n+2th number. To meet the time limit though, when implementing a fibonacci function, you'll want to cache results to speed everything up or the recursion will be far too slow.