Why is the time complexity of inserting an element into a set O(log N) and deletion O(N)?

Question

有人可以简要解释一下，我用谷歌搜索，但只发现时间复杂性而没有任何解释。

Answer 1

Why is the time complexity of inserting an element into a set O(log N) and deletion O(N)?

The former is accurate, but the latter is not true; both removal and insertion of elements is O(log N) time complexity :

std::set is an associative container that contains a sorted set of unique objects of type Key . Sorting is done using the key comparison function Compare . Search, removal, and insertion operations have logarithmic complexity . Sets are usually implemented as red-black trees.

The std::set is typically implemented as a red-black tree , which fulfills the complexity requirement placed on the std::set associative container:

[...] The insertion and deletion operations, along with the tree rearrangement and recoloring, are also performed in O(log n) time.