What happens if elements are added to a TreeSet in ascending order?

When adding elements to a TreeSet in ascending order, the internal structure (TreeMap) will be forced to perform rebalancing regularly. TreeSet stores elements in a red-black tree, which, when elements are added sequentially in sorted order, tends to degenerate into a linear structure (similar to a linked list).

Each operation of adding an element to the sorted TreeSet requires traversal, finding the insertion point, and possibly rebalancing to maintain the logarithmic complexity of most operations.

In terms of performance:

• The time to add each element remains on average O(log n), but the constant factor may be higher due to frequent rebalancing.
• The total time to build a TreeSet from N elements will be approximately O(N log N).

Although correctness is not compromised, adding elements in a different order (for example, randomly) could initially result in a more balanced tree, potentially reducing the number of rebalancing operations during construction.