public class Fraction
{
private int denominator, numerator;
public Fraction (int numerator, int denominator)
{
this.numerator = numerator;
this.denominator = denominator;
}
public void setNumerator (int numerator)
{
this.numerator = numerator;
}
public void setDenominator (int denominator)
{
this.denominator = denominator;
}
public double getNumerator ()
{
return (double)numerator;
}
public double getDenominator ()
{
return (double)denominator;
}
private static int GCD (int small, int large)
{
int div;
for (div = small; div > 0; div--)
{
if (large%div == 0 && small%div == 0)
return div;
}
return div;
}
public void simplify ()
{
int div = GCD (numerator, denominator);
numerator = numerator / div;
denominator = denominator / div;
}
public String toString ()
{
String s = numerator + " / " + denominator;
return s;
}
}
import java.util.Scanner;
public class FractionTest
{
public static void main(String[] args)
{
Scanner keyboard = new Scanner (System.in);
int num, denom;
System.out.println ("Enter numerator: ");
num = keyboard.nextInt ();
System.out.println ("Enter denominator: ");
denom = keyboard.nextInt ();
Fraction f = new Fraction (num, denom);
System.out.println (f);
System.out.println (f.getNumerator() / f.getDenominator());
f.simplify ();
System.out.println (f);
}
}
//class to operate a number of hot dog stands
public class HotDogStand
{
private int ID;
private int count;
private static int totalCount;
public HotDogStand (int ID, int count)
{
this.ID = ID;
this.count = count;
}
public void justSold ()
{
this.count++;
totalCount++;
}
public int getCount ()
{
return count;
}
public static int getTotalCount ()
{
return totalCount;
}
public String toString ()
{
String s = "Stand no " + ID + " has sold " + count + " hot dogs.";
return s;
}
}
//test hot dog stand
import java.util.Scanner;
public class HotDogStandTest
{
public static void main (String [] args)
{
Scanner kb = new Scanner (System.in);
HotDogStand stand1, stand2, stand3;
int stand;
stand1 = new HotDogStand (1, 0);
stand2 = new HotDogStand (2, 0);
stand3 = new HotDogStand (3, 0);
do
{
System.out.print ("Which stand has sold (1, 2 or 3) - 0 for Exit? ");
stand = kb.nextInt ();
if (stand == 1)
stand1.justSold ();
else if (stand == 2)
stand2.justSold ();
else if (stand == 3)
stand3.justSold ();
}while (stand != 0);
System.out.println (stand1);
System.out.println (stand2);
System.out.println (stand3);
System.out.println (HotDogs.getTotalCount() + " sold in total");
}
}
import java.util.Scanner;
public class GradeBook
{
private int numberOfStudents; // Same as studentAverage.length.
private int numberOfQuizzes; // Same as quizeAverage.length.
private int[][] grade; //numberOfStudents rows and numberOfQuizzes columns.
private double[] studentAverage;
private double[] quizAverage;
public GradeBook(int[][] a)
{
if (a.length == 0 || a[0].length == 0)
{
System.out.println("Empty grade records. Aborting.");
System.exit(0);
}
numberOfStudents = a.length;
numberOfQuizzes = a[0].length;
fillGrade(a);
fillStudentAverage( );
fillQuizAverage( );
}
public GradeBook(GradeBook book)
{
numberOfStudents = book.numberOfStudents;
numberOfQuizzes = book.numberOfQuizzes;
fillGrade(book.grade);
fillStudentAverage( );
fillQuizAverage( );
}
public GradeBook( )
{
Scanner keyboard = new Scanner(System.in);
System.out.println("Enter number of students:");
numberOfStudents = keyboard.nextInt( );
System.out.println("Enter number of quizzes:");
numberOfQuizzes = keyboard.nextInt( );
grade = new int[numberOfStudents][numberOfQuizzes];
for (int studentNumber = 1;
studentNumber <= numberOfStudents; studentNumber++)
for (int quizNumber = 1;
quizNumber <= numberOfQuizzes; quizNumber++)
{
System.out.println("Enter score for student number "
+ studentNumber);
System.out.println("on quiz number " + quizNumber);
grade[studentNumber - 1][quizNumber - 1] =
keyboard.nextInt( );
}
fillStudentAverage( );
fillQuizAverage( );
}
private void fillGrade(int[][] a)
{
grade = new int[numberOfStudents][numberOfQuizzes];
for (int studentNumber = 1;
studentNumber <= numberOfStudents; studentNumber++)
{
for (int quizNumber = 1;
quizNumber <= numberOfQuizzes; quizNumber++)
grade[studentNumber][quizNumber] =
a[studentNumber][quizNumber];
}
}
/**
Fills the array studentAverage using the data from the array grade.
*/
private void fillStudentAverage( )
{
studentAverage = new double[numberOfStudents];
for (int studentNumber = 1;
studentNumber <= numberOfStudents; studentNumber++)
{//Process one studentNumber:
double sum = 0;
for (int quizNumber = 1;
quizNumber <= numberOfQuizzes; quizNumber++)
sum = sum + grade[studentNumber - 1][quizNumber - 1];
//sum contains the sum of the quiz scores for student number studentNumber.
studentAverage[studentNumber - 1] = sum/numberOfQuizzes;
//Average for student studentNumber is studentAverage[studentNumber - 1]
}
}
/**
Fills the array quizAverage using the data from the array grade.
*/
private void fillQuizAverage( )
{
quizAverage = new double[numberOfQuizzes];
for (int quizNumber = 1; quizNumber <= numberOfQuizzes; quizNumber++)
{//Process one quiz (for all students):
double sum = 0;
for (int studentNumber = 1;
studentNumber <= numberOfStudents; studentNumber++)
sum = sum + grade[studentNumber - 1][quizNumber - 1];
//sum contains the sum of all student scores on quiz number quizNumber.
quizAverage[quizNumber - 1] = sum/numberOfStudents;
//Average for quiz quizNumber is the value of quizAverage[quizNumber - 1]
}
}
public void display( )
{
for (int studentNumber = 1;
studentNumber <= numberOfStudents; studentNumber++)
{//Display for one studentNumber:
System.out.print("Student " + studentNumber + " Quizzes: ");
for (int quizNumber = 1;
quizNumber <= numberOfQuizzes; quizNumber++)
System.out.print(grade[studentNumber - 1][quizNumber - 1] + " ");
System.out.println(" Ave = " + studentAverage[studentNumber - 1] );
}
System.out.println("Quiz averages: ");
for (int quizNumber = 1; quizNumber <= numberOfQuizzes; quizNumber++)
System.out.print("Quiz " + quizNumber
+ " Ave = " + quizAverage[quizNumber - 1] + " ");
System.out.println( );
}
}
//test gradebook
public class GradeBookDemo
{
public static void main(String[] args)
{
GradeBook book = new GradeBook( );
book.display( );
}
}