> > here is input sequence like a1,a2,...,an,b1,b2,...,bn ，the ax and bx always > > exist in pair. So, now, how to change the sequence to a1,b1,...,an,bn, with > > time complexity as O(n) and space as O(1). > > > > The two halves of the list are already sorted, yes?
[Wesley] No, not sorted yet.. -- https://mail.python.org/mailman/listinfo/python-list
