Java程序辅导
C C++ Java Python Processing编程在线培训 程序编写 软件开发 视频讲解
C C++ Java Python Processing编程在线培训 程序编写 软件开发 视频讲解
Qianqian Wang
Homework 4
11/19/2014
1.
// Lab 1: Time2.java
// Time2 class definition with methods tick,
// incrementMinute and incrementHour.
public class Time2
{
private int hour; // 0 - 23
private int minute; // 0 - 59
private int second; // 0 - 59
// Time2 no-argument constructor: initializes each instance variable
// to zero; ensures that Time2 objects start in a consistent state
public Time2()
{
this( 0, 0, 0 ); // invoke Time2 constructor with three arguments
} // end Time2 no-argument constructor
// Time2 constructor: hour supplied, minute and second defaulted to 0
public Time2( int h )
{
this( h, 0, 0 ); // invoke Time2 constructor with three arguments
} // end Time2 one-argument constructor
// Time2 constructor: hour and minute supplied, second defaulted to 0
public Time2( int h, int m )
{
this( h, m, 0 ); // invoke Time2 constructor with three arguments
} // end Time2 two-argument constructor
// Time2 constructor: hour, minute and second supplied
public Time2( int h, int m, int s )
{
setTime( h, m, s ); // invoke setTime to validate time
} // end Time2 three-argument constructor
// Time2 constructor: another Time2 object supplied
public Time2( Time2 time )
{
// invoke Time2 constructor with three arguments
this( time.getHour(), time.getMinute(), time.getSecond() );
} // end Time2 constructor with Time2 argument
// Set a new time value using universal time. Perform
// validity checks on data. Set invalid values to zero.
/* Write header for setTime. */
public void setTime(int h, int m, int s)
{
/* Write code here that declares three boolean variables which are
initialized to the return values of setHour, setMinute and setSecond.
These lines of code should also set the three member variables. */
setHour( h);
setMinute( m);
setSecond( s);
/* Return true if all three variables are true; otherwise, return false. */
}
// validate and set hour
/* Write header for the setHour method. */
public void setHour(int h)
{
/* Write code here that determines whether the hour is valid.
If so, set the hour and return true. */
if (h >= 0 && h < 24)
hour = h;
else {
hour = 0;
throw new IllegalArgumentException( "Hours must be 0~23");
}
/* If the hour is not valid, set the hour to 0 and return false. */
}
// validate and set minute
/* Write the header for the setMinute method. */
public void setMinute(int m)
{
/* Write code here that determines whether the minute is valid.
If so, set the minute and return true. */
if ( m >=0 && m < 60)
minute = m;
else{
minute = 0;
throw new IllegalArgumentException(" Minutes must be 0~59");
}
/* If the minute is not valid, set the minute to 0 and return false. */
}
// validate and set second
/* Write the header for the setSecond method. */
public void setSecond(int s)
{
/* Write code here that determines whether the second is valid.
If so, set the second and return true. */
if (s >=0 && s < 60)
second = s;
else{
second = 0;
throw new IllegalArgumentException("Seconds must be 0~59");
}
/* If the second is not valid, set the second to 0 and return false. */
}
// Get Methods
// get hour value
public int getHour()
{
return hour;
} // end method getHour
// get minute value
public int getMinute()
{
return minute;
} // end method getMinute
// get second value
public int getSecond()
{
return second;
} // end method getSecond
// Tick the time by one second
public void tick()
{
setSecond( second + 1 );
if ( second == 0 )
incrementMinute();
} // end method tick
// Increment the minute
public void incrementMinute()
{
setMinute( minute + 1 );
if ( minute == 0 )
incrementHour();
} // end method incrementMinute
// Increment the hour
public void incrementHour()
{
setHour( hour + 1 );
} // end method incrementHour
// convert to String in universal-time format (HH:MM:SS)
public String toUniversalString()
{
return String.format(
"%02d:%02d:%02d", getHour(), getMinute(), getSecond() );
} // end method toUniversalString
// convert to String in standard-time format (H:MM:SS AM or PM)
public String toString()
{
return String.format( "%d:%02d:%02d %s",
( ( getHour() == 0 || getHour() == 12 ) ? 12 : getHour() % 12 ),
getMinute(), getSecond(), ( getHour() < 12 ? "AM" : "PM" ) );
} // end method toStandardString
} // end class Time2
// Lab 1: Time2Test.java
// Program adds validation to Fig. 8.7 example
import java.util.Scanner;
public class Time2Test
{
public static void main( String args[] )
{
Scanner input = new Scanner( System.in );
Time2 time = new Time2(); // the Time2 object
int choice = getMenuChoice();
while ( choice != 5 )
{
switch ( choice )
{
case 1: // set hour
System.out.print( "Enter Hours: " );
int hours = input.nextInt();
/* Write code here that sets the hour. If the hour is invalid,
display an error message. */
time.setHour(hours);
break;
case 2: // set minute
System.out.print( "Enter Minutes: " );
int minutes = input.nextInt();
/* Write code here that sets the minute. If the minute is invalid,
display an error message. */
time.setMinute(minutes);
break;
case 3: // set seconds
System.out.print( "Enter Seconds: " );
int seconds = input.nextInt();
/* Write code here that sets the second. If the second is invalid,
display an error message. */
time.setSecond(seconds);
break;
case 4: // add 1 second
time.tick();
break;
} // end switch
System.out.printf( "Hour: %d Minute: %d Second: %d\n",
time.getHour(), time.getMinute(), time.getSecond() );
System.out.printf( "Universal time: %s Standard time: %s\n",
time.toUniversalString(), time.toString() );
choice = getMenuChoice();
} // end while
} // end main
// prints a menu and returns a value corresponding to the menu choice
private static int getMenuChoice()
{
Scanner input = new Scanner( System.in );
System.out.println( "1. Set Hour" );
System.out.println( "2. Set Minute" );
System.out.println( "3. Set Second" );
System.out.println( "4. Add 1 second" );
System.out.println( "5. Exit" );
System.out.print( "Choice: " );
return input.nextInt();
} // end method getMenuChoice
} // end class Time2Test
I have finished this task successfully!
Score 10/10
2.
// Lab 3: Complex.java
// Definition of class Complex
public class Complex
{
private double real;
private double imaginary;
// Initialize both parts to 0
/* Write header for a no-argument constructor. */
public Complex()
{
/* Write code here that calls the Complex constructor that takes 2
arguments and initializes both parts to 0 */
real = 0;
imaginary = 0;
} // end Complex no-argument constructor
// Initialize real part to r and imaginary part to i
/* Write header for constructor that takes two arguments-real part r and
imaginary part i. */
public Complex (double r, double i)
{
/* Write line of code that sets real part to r. */
real = r;
/* Write line of code that sets imaginary part to i. */
imaginary = i;
}
// Add two Complex numbers
public Complex add( Complex right )
{
/* Write code here that returns a Complex number in which the real part is
the sum of the real part of this Complex object and the real part of the
Complex object passed to the method; and the imaginary part is the sum
of the imaginary part of this Complex object and the imaginary part of
the Complex object passed to the method. */
Complex temp = new Complex (this.real, this.imaginary);
temp.real = temp.real + right.real;
temp.imaginary = this.imaginary + right.imaginary;
return temp;
}
// Subtract two Complex numbers
public Complex subtract( Complex right )
{
/* Write code here that returns a Complex number in which the real part is
the difference between the real part of this Complex object and the real
part of the Complex object passed to the method; and the imaginary part
is the difference between the imaginary part of this Complex object and
the imaginary part of the Complex object passed to the method. */
Complex temp = new Complex (this.real, this.imaginary);
temp.real = temp.real - right.real;
temp.imaginary = this.imaginary - right.imaginary;
return temp;
}
// Return String representation of a Complex number
public String toString()
{
return String.format( "(%.1f, %.1f)", real, imaginary );
} // end method toComplexString;
} // end class Complex
// Exercise 8.12: ComplexTest.java
// Test the Complex number class
public class ComplexTest
{
public static void main( String args[] )
{
// initialize two numbers
Complex a = new Complex( 9.5, 7.7 );
Complex b = new Complex( 1.2, 3.1 );
System.out.printf( "a = %s\n", a );
System.out.printf( "b = %s\n", b );
System.out.printf( "a + b = %s\n", a.add( b ) );
System.out.printf( "a - b = %s\n", a.subtract( b ) );
} // end main
} // end class ComplexTest
I have finished this task successfully!
Score: 10/10
3.
// Lab Exercise 1: PieceWorker.java
// PieceWorker class extends Employee.
public class PieceWorker extends Employee
{
/* declare instance variable wage */
private double wage;
/* declare instance variable pieces */
private double pieces;
// five-argument constructor
public PieceWorker( String first, String last, String ssn,
double wagePerPiece, int piecesProduced )
{
/* write code to initialize a PieceWorker */
super(first,last,ssn);
setWage( wagePerPiece);
} // end five-argument PieceWorker constructor
// set wage
/* write a set method that validates and sets the PieceWorker's wage */
public void setWage(double wagedWork)
{
wage = wagedWork;
}
// return wage
/* write a get method that returns the PieceWorker's wage */
public double getWage()
{
return wage;
}
// set pieces produced
/* write a set method that validates and sets the number of pieces produced */
public void setPieces(double piecesMade)
{
pieces = piecesMade;
}
// return pieces produced
/* write a get method that returns the number of pieces produced */
public double getPieces()
{
return pieces;
}
// calculate earnings; override abstract method earnings in Employee
public double earnings()
{
/* write code to return the earnings for a PieceWorker */
return getWage() * getPieces();
} // end method earnings
// return String representation of PieceWorker object
public String toString()
{
/* write code to return a string representation of a PieceWorker */
return String.format(" %s: %s\n%s: $%,.2f\n%s:%.2f","Piecework Employee",
super.toString(),"wage is",getWage(),"number of pieces",getPieces(),earnings());
} // end method toString
} // end class PieceWorker
// Lab Exercise 1: PayrollSystemTest.java
// Employee hierarchy test program.
public class PayrollSystemTest
{
public static void main( String args[] )
{
// create five-element Employee array
Employee employees[] = new Employee[ 5 ];
// initialize array with Employees
employees[ 0 ] = new SalariedEmployee(
"John", "Smith", "111-11-1111", 800.00 );
employees[ 1 ] = new HourlyEmployee(
"Karen", "Price", "222-22-2222", 16.75, 40 );
employees[ 2 ] = new CommissionEmployee(
"Sue", "Jones", "333-33-3333", 10000, .06 );
employees[ 3 ] = new BasePlusCommissionEmployee(
"Bob", "Lewis", "444-44-4444", 5000, .04, 300 );
/* create a PieceWoker object and assign it to employees[ 4 ] */
employees[ 4 ] = new PieceWorker(
"Emily", "Wang", "555-55-5555", 87.23, 234);
System.out.println( "Employees processed polymorphically:\n" );
// generically process each element in array employees
for ( Employee currentEmployee : employees )
{
System.out.println( currentEmployee ); // invokes toString
System.out.printf(
"earned $%,.2f\n\n", currentEmployee.earnings() );
} // end for
} // end main
} // end class PayrollSystemTest
I have finished this task successfully! Score: 10/10
4.
The relationship that exists between these classes is an “is-a” relationship. An
undergraduateStudent is a student, and also, a graduateStudent is a student. These classes
freshman, sophomore, junior, senior student is undergraduateStudent, and at the same time,
each of them is a student. MastersStudent, and DoctoralStudent is a graduatestudent. They are
also student. Inheritance makes it easy for someone to extend an idea further. This saves a lot of
time coding and a lot of time developing new methods for things that are already created.
Score:10/10
5.
//integer that returns the number with its digits reversed
import java.util.Scanner;
public class Reverse
{
public static void main(String args[])
{
Scanner input = new Scanner(System.in);
int num; //defines number as integer
int r = 0; //defines the reverse
System.out.printf("Enter an integer: "); //ask user for number
num = input.nextInt(); //input the number
while (num != 0)
{
r = r * 10 + num % 10;
num = num / 10;
}
System.out.printf("Reverse integer is %d", r);
}
}
I have finished this task successfully!
Score:10/10
6.
//determines if parameter number is a perfect number
import java.io.*;
import java.util.Scanner;
public class Perfect
{
public static void main( String args[]) throws IOException
{
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
System.out.print("\nEnter a number:");
int n = Integer.parseInt(br.readLine());
int sum = 0;
for(int i = 1;i < n;i++)
{
if(n%i == 0)
{
sum = sum + i;
}
}
if(sum == n)
System.out.println("\nGiven number is a perfect number");
else
System.out.println("\nGiven number is not perfect number");
}
}
//Java program to display perfect numbers in a given range
//range 1~1000
//range larger than 1000
import java.io.*;
class PerfectList
{
public static void main(String[] args) throws IOException
{
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
System.out.print("\nEnter the range:");
long range = Long.parseLong(br.readLine());
System.out.println("\nThe perfect numbers between 1 and "+range+" are:");
for(int i=1;i