On Sat, 1 Aug 2020 at 03:00, Inada Naoki <songofacandy@gmail.com> wrote:
Please teach me if you know any algorithm which has no hole, O(1)
deletion, preserving insertion order, and efficient and fast as array.


About the hole, I was thinking that in theory the problem can be circumvented using a modified version of lookdict.
lookdict searches for a key and returns its position in the ma_keys array. I suppose it's possible to do the contrary: search for the index and return the key.
What do you think (theoretically speaking)?