Prentice.Hall.Introduction.to.Java.Programming,.Brief.Version.9th.(2014).[sharethefiles.com]

174 Chapter 4 Loops
*4.42 (Financial application: find the sales amount) Rewrite Exercise 4.39 as follows:
■ Use a for loop instead of a do-while loop.
■ Let the user enter COMMISSION_SOUGHT instead of fixing it as a constant.
*4.43 (Simulation: clock countdown) Write a program that prompts the user to enter the
number of seconds, displays a message at every second, and terminates when the
time expires. Here is a sample run:
Enter the number of seconds:
2 seconds remaining
1 second remaining
Stopped
3
**4.44 (Monte Carlo simulation) A square is divided into four smaller regions as shown
below in (a). If you throw a dart into the square 1,000,000 times, what is the probability
for a dart to fall into an odd-numbered region? Write a program to simulate
the process and display the result.
(Hint: Place the center of the square in the center of a coordinate system, as shown
in (b). Randomly generate a point in the square and count the number of times for
a point to fall into an odd-numbered region.)
1
3
4
2
1
3
4
2
(a)
(b)
*4.45 (Math: combinations) Write a program that displays all possible combinations for
picking two numbers from integers 1 to 7. Also display the total number of all
combinations.
1 2
1 3
...
...
The total number of all combinations is 21
*4.46 (Computer architecture: bit-level operations) A short value is stored in 16 bits.
Write a program that prompts the user to enter a short integer and displays the 16
bits for the integer. Here are sample runs:
Enter an integer: 5
The bits are 0000000000000101