This week's book giveaway is in the OO, Patterns, UML and Refactoring forum. We're giving away four copies of Refactoring for Software Design Smells: Managing Technical Debt and have Girish Suryanarayana, Ganesh Samarthyam & Tushar Sharma on-line! See this thread for details.
It is quite easy to put keys or values into a Map, but you need to put them in pairs. If your elements from the Map go as Keys, what would you use as Values? If your elements from the Map go as Values, what would you use as Keys?