Am I one of the 10% of programmers who can write a binary search?

I think I might be! After reading an article claiming that only 10% of programmers can write a binary search I decided to give it a shot. After about 20 minutes, I came up with this:

            def bsearch(array, search, start_ix=0, end_ix=array.length)
                mid_ix = start_ix + ((end_ix-start_ix)/2).ceil
                if array[mid_ix] == search then
                    puts "%d found at position %d" % [ search, mid_ix]
                elsif start_ix == mid_ix then
                    puts "%d not found" % [ search ]
                elsif array[mid_ix] < search
                    bsearch(array, search, mid_ix, end_ix)
                elsif array[mid_ix] > search then
                    bsearch(array, search, start_ix, mid_ix)
                end
            end
            
            bsearch([10, 20, 30, 40, 50, 60, 70, 80, 90], ARGV[0].to_i)
            

It’s probably not by best work, and I’m pretty doubtful that I could have done it in the same amount of time under the stress of a job interview. But it works, and that’s good enough for me, considering that I haven’t been a full time programmer in quite some time and haven’t written anything like this since college. ;-)