Write a program segment that defines a file stream object named employees. The file should be opened for both input and output (in binary mode). If the file fails to open, the program segment should display an error message.

Use the web to determine the current world population and the annual world population growth rate. Write an application that inputs these values, then displays the estimated world population after one, two, three, four and five years.

One problem in CAI environments is student fatigue. This can be reduced by varying the computer’s responses to hold the student’s attention. Modify the program of previous exercise. So that various comments are displayed for each answer as follows:

Possible responses to a correct answer:

• Very good!
• Excellent!
• Nice work!
• Keep up the good work!

Possible responses to an incorrect answer:

• No. Please try again.
• Wrong. Try once more.
• Don't give up!
• No. Keep trying.

Use random-number generation to choose a number from 1 to 4 that will be used to select one of the four appropriate responses to each correct or incorrect answer. Use a switch statement to issue the responses.

A large company pays its salespeople on a commission basis. The salespeople receive $200 per week plus 9% of their gross sales for that week. For example, a salesperson who sells$5000 worth of merchandise in a week receives $200 plus 9% of$5000, or a total of $650. You’ve been supplied with a list of the items sold by each salesperson. The values of these items are as follows:

Item    Value
1        239.99
2       129.75
3       99.95
4      350.89

Develop a Java application that inputs one salesperson’s items sold for last week and calculates and displays that salesperson’s earnings. There’s no limit to the number of items that can be sold.

Create a class Rectangle with attributes length and width, each of which defaults to 1. Provide methods that calculate the rectangle’s perimeter and area. It has set and get methods for both length and width. The set methods should verify that length and width are each floating-point numbers larger than 0.0 and less than 20.0.Write a program to test class Rectangle.Create class SavingsAccount. Use a static variable annualInterestRate to store the annual interest rate for all account holders. Each object of the class contains a private instance variable savingsBalance indicating the amount the saver currently has on deposit. Provide method calculateMonthlyInterest to calculate the monthly interest by multiplying the savingsBalance by annualInterestRate divided by 12—this interest should be added to savings- Balance. Provide a static method modifyInterestRate that sets the annualInterestRate to a new value. Write a program to test class SavingsAccount. Instantiate two savingsAccount objects, saver1 and saver2, with balances of $2000.00 and$3000.00, respectively. Set annualInterestRate to 4%, then calculate the monthly interest for each of 12 months and print the new balances for both savers. Next, set the annualInterestRate to 5%, calculate the next month’s interest and print the new balances for both savers.

Write an application that inputs one number consisting of five digits from the user, separates the number into its individual digits and prints the digits separated from one another by three spaces each. For example, if the user types in the number 42339, the program should print

4 2 3 3 9

Assume that the user enters the correct number of digits. What happens when you execute the program and type a number with more than five digits? What happens when you execute the program and type a number with fewer than five digits? [Hint: It’s possible to do this exercise with the techniques you learned in this chapter. You’ll need to use both division and remainder operations to “pick off ” each digit.]

While exercising, you can use a heart-rate monitor to see that your heart rate stays within a safe range suggested by your trainers and doctors. According to the American Heart Association (AHA) (www.americanheart.org/presenter.jhtml?identifier=4736), the formula for calculating your maximum heart rate in beats per minute is 220 minus your age in years. Your target heart rate is a range that’s 50–85% of your maximum heart rate. [Note: These formulas are estimates provided by the AHA. Maximum and target heart rates may vary based on the health, fitness and gender of the individual. Always consult a physician or qualified health care professional before beginning or modifying an exercise program.] Create a class called HeartRates. The class attributes should include the person’s first name, last name and date of birth (consisting of separate attributes for the month, day and year of birth). Your class should have a constructor that receives this data as parameters. For each attribute provide set and get methods. The class also should include a method that calculates and returns the person’s age (in years), a method that calculates and returns the person’s maximum heart rate and a method that calculates and returns the person’s target heart rate. Write a Java application that prompts for the person’s information, instantiates an object of class HeartRates and prints the information from that object—including the person’s first name, last name and date of birth—then calculates and prints the person’s age in (years), maximum heart rate and target-heart-rate range.

Drivers are concerned with the mileage their automobiles get. One driver has kept track of several trips by recording the miles driven and gallons used for each tankful. Develop a Java application that will input the miles driven and gallons used (both as integers) for each trip. The program should calculate and display the miles per gallon obtained for each trip and print the combined miles per gallon obtained for all trips up to this point. All averaging calculations should produce floating-point results. Use class Scanner and sentinel-controlled repetition to obtain the data from the user.

Perform an asymptotic analysis of the insertion-sort algorithm. What are the worst-case and best-case running times?

Create class DateAndTime that combines the modified Time2 class of earlier Exercise and the modified Date class of previous exercise. Modify method incrementhour to call method nextDay if the time is incremented into the next day. Modify methods toString and toUniversalString to output the date in addition to the time. Write a program to test the new class DateAndTime. Specifically, test incrementing the time to the next day.

Complete the following program skeleton by writing a switch statement that displays “one” if the user has entered 1, “two” if the user has entered 2, and “three” if the user has entered 3. If a number other than 1, 2, or 3 is entered, the program should display an error message

import java.util.Scanner;

public class CheckPoint

{

 public static void main(String[ ] args)

 {

 int userNum;

 Scanner keyboard = new Scanner(System.in);

 System.out.print("Enter one of the numbers " +

 "1, 2, or 3: ");

 userNum = keyboard.nextInt():

 //

 // Write the switch statement here.

 //

 }

}

A program contains the following function.

void display(int arg1, double arg2, char arg3)
{
    cout << "Here are the values: "
         << arg1 << " " << arg2 << " " << arg3 << endl;
}

A program contains the following function.

void display(int arg1, double arg2, char arg3)
{
    cout << "Here are the values: "
         << arg1 << " " << arg2 << " " << arg3 << endl;
}

Write a statement that calls the function and passes the following variables to it:

int age;
double income;
char initial;

Research several car-pooling websites. Create an application that calculates your daily driving cost, so that you can estimate how much money could be saved by car pooling, which also has other advantages such as reducing carbon emissions and reducing traffic congestion. The application should input the following information and display the user’s cost per day of driving to work:

a) Total miles driven per day.

b) Cost per gallon of gasoline.

c) Average miles per gallon.

d) Parking fees per day.

e) Tolls per day.

Write a Java method that takes two three-dimensional integer arrays and adds them componentwise.