Write a method in the HashIntSet class called containsAll that accepts another hash set as a parameter and returns true if your set contains every element from the other set. For example, if the set stores [-2, 3, 5, 6, 8] and the method is passed [3, 6, 8], your method would return true. If the method were passed [3, 6, 7, 8], your method would return false because your set does not contain the value 7.

Suppose there is a relation r(a, b, c) with a b+-tree index with search keys (a, b).1. what is the worst-case cost of finding records satisfying 10 < a < 50 using this index, in terms of the number of records n1, retrieved and the height h of the tree? 2. what is the worst-case cost of finding records satisfying 10 < a < 50 and 5 < b < 10 using this index, in terms of the number of records n2 that satisfy this selection, as well as n1 and h defined above? 3. under what conditions on n1 and n2, would the index be an efficient way of finding records satisfying the condition from part (2)?