The source code for Problem Solving with Java, 2nd edition, Koffman and Wolz,  
consists of 11 folders, one for each chapter (Chapter1, Chapter2, and so on), 
and a folder named psJava. The folder for each chapter contains separate 
subdirectories. The name of each subdirectory indicates the textbook figures 
(classes) that are in that subdirectory. For example, folder Chapter3\Fig3_14-15 
contains the classes shown in Fig. 3.14 (CoinChanger, p. 130-131) and Fig. 3.15 
(ChangeCoinsApp, p.132). Both classes are used in the solution to the coin 
changer problem (p.127).

Package psJava consists of 4 classes: KeyIn, ConsoleIn, IntArray, and Sorts 
described below.

KeyIn:  Contains a collection of static methods (readInt, readString, 
readDouble, readChar, readBoolean, readChoice) for performing input operations 
using dialog windows (see pp. 153-155, 185-186, 247, 306). Class KeyIn uses 
methods from Swing's JOptionPane class to display the dialog windows.

ConsoleIn: Contains the same static methods as class KeyIn; however, these 
methods read data from the console window instead of through dialog windows. 
Some Unix users may find this class easier to use than class KeyIn. In systems 
with limited memory, class ConsoleIn may provide better performance than class 
KeyIn. 

IntArray: Contains a collection of static methods (search, selectionSort, 
findPosMin, findMedian) for searching and sorting an array of integers and 
finding the median value in the array (p. 298-303).

Sorts: Contains a selection sort method for sorting arrays of type Comparable[] 
(p. 398-401).