On 15 July 2017 at 04:01, Max Moroz <maxmo...@gmail.com> wrote: > What would be the disadvantage of implementing collections.deque as a > circular array (rather than a doubly linked list of blocks)? My naive > thinking was that a circular array would maintain the current O(1) append/pop > from either side, and would improve index lookup in the middle from O(n) to > O(1). What am I missing? > > The insertion/removal of an arbitrary item specified by a pointer would > increase from constant time to linear, but since we don't have pointers > this is a moot point. > > Of course when the circular array is full, it will need to be reallocated, > but the amortized cost of that is still O(1). (Moreover, for a bounded > deque, there's even an option of preallocation, which would completely > eliminate reallocations.) >
Now - since you are at it, you could possibly mine pypi for interesting efficient data structures that could cover use cases lists and deque not suffice. I am pretty sure one could find a couple, - and once we get a few that are well behaved and somewhat popular, they could be made candidates for inclusion in collections, I guess. > Thanks > > Max > > _______________________________________________ > Python-Dev mailing list > Python-Dev@python.org > https://mail.python.org/mailman/listinfo/python-dev > Unsubscribe: https://mail.python.org/mailman/options/python-dev/ > jsbueno%40python.org.br > >
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