# Insert/Delete/GetRandom: O(1)

- [380. Insert Delete GetRandom O(1)](/lcbook/design/untitled/380.-insert-delete-getrandom-o-1.md)
- [381. Insert Delete GetRandom O(1) - Duplicates allowed](/lcbook/design/untitled/381.-insert-delete-getrandom-o-1-duplicates-allowed.md)
