Below are some computational tasks. For each one of these tasks, choose the data structure or abstract data type you feel is best suited to perform the task from the following list: Stack, Queue, Hashtable, AVL Tree, Priority Queue. In addition, list the basic operations for the data structure or ADT that you chose and give asymptotic worst-case running times for those operations. No additional explanation is required. 2.1 While processing a list of objects, check if you have processed a particular object before.