To Notes

CSC 212 -- 1/31/08

Review Questions

1. Construct a trace table for the InsertionSort Algorithm for this array:

   42  26  19  35  21  59  40
   

2. Modify the FindMin.java example so that it finds the Person object of minimum age.

3. Modify the InsertionSort.java Example so that it sorts Person objects.

Sorting

• Look at the SelectionSort Example:   SelectionSort.java

• Trace the SelectionSort sorting algorithm using this table:

  i	j	a[0]	a[1]	a[2]	a[3]	a[4]	temp
  		45	34	76	53	40

  Add more rows in the table as needed.

• Modify the SelectionSort Example to sort Person objects.

Reading Data from a File

• The following code creates a Scanner object from System.io:

  Scanner s = new Scanner(System.io);
  

• To read from the file filename.txt in the current directory:

  FileReader fr = new FileReader("filename.txt");
  Scanner s = new Scanner(System.io);
  

• In addition:
  1. Import System.util.Scanner and java.io.*.

  2. Modify the header of the main method:

     public static void main(String[ ] argv) 
                             throws FileNotFoundException
     

• Using a relative path name like numbers.txt will not work with BlueJ. Instead, use an absolute path name like "c:\\ssmith\\numbers.txt". The character '\\' is the escape sequence for a single backslash.

• See the LoadFromFile Example: LoadFromFile.java. Here is the input file: numbers.txt.

• See the FindGender Example FindGender.java   Person.java. Here is the input file: persons.txt.