Linked lists

A linked-list is a data structure that is built by composing nodes. Each node contains a data part and one or two links that are pointers to adjacent nodes in the sequence. A singly linked list has one pointer that points to the next node in the sequence. A doubly linked list has an additional pointer that points to the previous node in the sequence. The new and delete operators are used to allocate and deallocate nodes as needed by the list.