I need a data structure which:
1) I will be able to remove an item (without knowing the index of that item)
2) I can draw an item randomly (normally in an array, I generate a random number and draw that item in that index.. data structures that use keys -hashtables, hashmaps vs need an iterator to go through the items)
3) I will be able to add an item (the adding order does not matter)
Which data structure gives faster solutions?