Question

I was looking for some simple implemented data structure which gets my needs fulfilled in least possible time (in worst possible case) :-

(1)To pop nth element (I have to keep relative order of elements intact)
(2)To access nth element .

I couldn’t use array because it can’t pop and i dont want to have a gap after deleting ith element . I tried to remove the gap , by exchanging nth element with next again with next untill last but that proves time ineffecient though array’s O(1) is unbeatable .

I tried using vector and used ‘erase’ for popup and ‘.at()’ for access , but even this is not cheap for time effeciency though its better than array .

Answer 1

What you can try is skip list – it support the operation you are requesting in O(log(n)). Another option would be tiered vector that is just slightly easier to implement and takes O(sqrt(n)). both structures are quite cool but alas not very popular.