The implementations of the ADT dictionary given in this chapter make the following assumption: At any time, a dictionary contains at most one item with a given search key. Although the definition of...

The implementations of the ADT dictionary given in this chapter make the following assumption: At any time, a dictionary contains at most one item with a given search key. Although the definition of the ADT required for a specific application may not allow duplicates, it is probably wise to test for them rather than simply to assume that they will not occur. Why? Modify the dictionary implementations so that they test for—and disallow—any duplicates. What dictionary operations are affected? What are the implications for the unsorted linear implementations?