The STL (Standard Template Library) in C++ provides many common data structures used in day-to-day programming. The purpose of the STL is to provide some common code that many programs are expected to use, so software developers don't have to "reinvent the wheel" every time they write a new program. In this lab we'll explore the use of a map, which holds a (key, value) pair and provides fast retrieval of a value, given a key.