An array is sparse if most of its entries are null. A list L can be used to implement such an array, A, efficiently. In particular, for each nonnull cell A[i], we can store a pair (i,e) in L, where e is the element stored at A[i]. This approach allows us to represent A using O(m) storage, where m is the number of nonnull entries in A. Describe and analyze efficient ways of performing the methods of the array list ADT on such a representation.