Sequence
A sequence is a container of elements, indexed by a set of contiguous non-negative integers (i.e. there is ordering).
Common Operations
insert(val, idx)append(val)at(idx)remove(idx)
Implementing

A sequence is a container of elements, indexed by a set of contiguous non-negative integers (i.e. there is ordering).
insert(val, idx)append(val)at(idx)remove(idx)