Here is part A of the program that will work with this type of input data file. Of course, there are some blanks for you to fill.
import java.io.*; import java.util.Scanner; class TestGroupsSentinel { public static void main ( String[] args ) throws IOException { int value; // the value of the current integer // Prompt for and open the input file Scanner user = new Scanner( System.in ); System.out.print("File name? "); String fileName = user.next().trim(); Scanner scan = new Scanner( new File(fileName) ); // Group "A" int sumA = ; // the sum of scores for group "A" int countA = ; // initialize the group A count while ( (value = scan.nextInt()) != -1 ) { sumA = sumA + ; // add to the sum countA = countA + 1; // increment the count } if ( countA > ) System.out.println( "Group A average: " + ((double) sumA)/countA ); else System.out.println( "Group A has no students" );
Of course, you are eager to fill in those blanks.