lion4464 / oopthink

In this Directory we are going to create some packages to use everywhere

OOPthink

In this Directory we are going to create some packages to use everywhere

oopthink's Issues

(Display the prime factors)

Write a program that prompts the user to enter a
positive integer and displays all its smallest factors in decreasing order. For
example, if the integer is 120, the smallest factors are displayed as 5, 3, 2, 2,
2. Use the StackOfIntegers class to store the factors (e.g., 2, 2, 2, 3, 5) and
retrieve and display them in reverse order.

(Divisible by 2 or 3)

Find the first 10 numbers with 50 decimal digits that are
divisible by 2 or 3.

(Geometry: the MyRectangle2D class)

Define the MyRectangle2D class that
contains:
■■ Two double data fields named x and y that specify the center of the rectangle
with getter and setter methods. (Assume the rectangle sides are parallel to
x- or y-axis.)
■■ The data fields width and height with getter and setter methods.
■■ A no-arg constructor that creates a default rectangle with (0, 0) for (x, y) and
1 for both width and height.
■■ A constructor that creates a rectangle with the specified x, y, width, and
height.
■ A method getArea() that returns the area of the rectangle.
■■ A method getPerimeter() that returns the perimeter of the rectangle.
■■ A method contains(double x, double y) that returns true if the
specified point (x, y) is inside this rectangle (see Figure 10.24a).
■■ A method contains(MyRectangle2D r) that returns true if the specified
rectangle is inside this rectangle (see Figure 10.24b).
■■ A method overlaps(MyRectangle2D r) that returns true if the specified
rectangle overlaps with this rectangle (see Figure 10.24c).

(The Queue class)

a class for Stack. Design a class named
Queue for storing integers. Like a stack, a queue holds elements. In a stack, the
elements are retrieved in a last-in first-out fashion. In a queue, the elements are
retrieved in a first-in first-out fashion. The class contains:
■■ An int[] data field named elements that stores the int values in the queue.
■■ A data field named size that stores the number of elements in the queue.
■■ A constructor that creates a Queue object with default capacity 8.
■■ The method enqueue(int v) that adds v into the queue.
■ The method dequeue() that removes and returns the element from the
queue.
■■ The method empty() that returns true if the queue is empty.
■■ The method getSize() that returns the size of the queue.
Draw an UML diagram for the class. Implement the class with the initial array
size set to 8. The array size will be doubled once the number of the elements
exceeds the size. After an element is removed from the beginning of the array,
you need to shift all elements in the array one position the left. Write a test
program that adds 20 numbers from 1 to 20 into the queue then removes these
numbers and displays them

(Game: ATM machine)

Use the Account class created in Programming Exercise 9.7 to simulate an ATM machine. Create 10 accounts in an array with id 0,
1, . . . , 9, and an initial balance of $100. The system prompts the user to enter
an id. If the id is entered incorrectly, ask the user to enter a correct id. Once an
id is accepted, the main menu is displayed as shown in the sample run. You can
enter choice 1 for viewing the current balance, 2 for withdrawing money, 3 for
depositing money, and 4 for exiting the main menu. Once you exit, the system
will prompt for an id again. Thus, once the system starts, it will not stop

(The MyPoint class)

Design a class named MyPoint to represent a point with
x- and y-coordinates. The class contains:
■■ The data fields x and y that represent the coordinates with getter methods.
■■ A no-arg constructor that creates a point (0, 0).
■■ A constructor that constructs a point with specified coordinates.
■■ A method named distance that returns the distance from this point to a
specified point of the MyPoint type.
■■ A method named distance that returns the distance from this point to
another point with specified x- and y-coordinates.
■■ A static method named distance that returns the distance from two MyPoint
objects.
Draw the UML diagram for the class then implement the class. Write a test
program that creates the two points (0, 0) and (10, 30.5) and displays the distance between them.

(Square numbers)

Find the first 10 square numbers that are greater than Long.
MAX_VALUE. A square number is a number in the form of n2. For example, 4, 9,
and 16 are square numbers. Find an efficient approach to run your program fast

(Geometry: the Circle2D class)

Define the Circle2D class that contains:
■■ Two double data fields named x and y that specify the center of the circle
with getter methods.
■■ A data field radius with a getter method.
■■ A no-arg constructor that creates a default circle with (0, 0) for (x, y) and 1
for radius.
■■ A constructor that creates a circle with the specified x, y, and radius.
■■ A method getArea() that returns the area of the circle.
■■ A method getPerimeter() that returns the perimeter of the circle.
■■ A method contains(double x, double y) that returns true if the
specified point (x, y) is inside this circle (see Figure 10.21a).
■■ A method contains(Circle2D circle) that returns true if the specified
circle is inside this circle (see Figure 10.21b).
■■ A method overlaps(Circle2D circle) that returns true if the specified
circle overlaps with this circle (see Figure 10.21c).