OBJECT-ORIENTED THINKING - Introduction to Java Programming: Comprehensive Version - page 403

The method dequeue() that removes and returns the element from the
queue.

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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 and removes these
numbers and displays them.

*10.11

( 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.

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A data field radius with a getter method.

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A no-arg constructor that creates a default circle with ( 0 , 0 ) for ( x , y ) and 1
for radius .

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A constructor that creates a circle with the specified x , y , and radius .

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A method getArea() that returns the area of the circle.

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A method getPerimeter() that returns the perimeter of the circle.

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A method contains(double x, double y) that returns true if the
specified point ( x , y ) is inside this circle (see Figure 10.21a).

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A method contains(Circle2D circle) that returns true if the speci-
fied circle is inside this circle (see Figure 10.21b).

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A method overlaps(Circle2D circle) that returns true if the speci-
fied circle overlaps with this circle (see Figure 10.21c).

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p

(a) (b) (c)

F IGURE 10.21

(a) A point is inside the circle. (b) A circle is inside another circle. (c) A circle
overlaps another circle.

Draw the UML diagram for the class and then implement the class. Write a test
program that creates a Circle2D object c1 ( new Circle2D(2, 2, 5.5) ),
displays its area and perimeter, and displays the result of c1.contains(3,
3) , c1.contains(new Circle2D(4, 5, 10.5)) , and c1.overlaps(new
Circle2D(3, 5, 2.3)) .

***10.12

( Geometry: the Triangle2D class ) Define the Triangle2D class that contains:

Three points named p1 , p2 , and p3 of the type MyPoint with getter and
setter methods. MyPoint is defined in Programming Exercise 10.4.

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A no-arg constructor that creates a default triangle with the points ( 0 , 0 ), ( 1 ,
1 ), and ( 2 , 5 ).

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A constructor that creates a triangle with the specified points. ■

A method getArea() that returns the area of the triangle.

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A method getPerimeter() that returns the perimeter of the triangle.

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A method contains(MyPoint p) that returns true if the specified point
p is inside this triangle (see Figure 10.22a).

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