Assignment 1 basic Java syntax

Assignment 1

Objective
This assignment should help you gain practice with basic Java syntax using procedural
programming, functions, arrays, and console I/O.
Task
Do the following three exercises each in a different file. Your filenames should be
 Pi.java
 Reverse.java
 DiceStats.java
Each file should have a comment including your name at the top of the file. Each file
should also have appropriate comments throughout the program.
To do the console input for these exercises, use the java.util.Scanner class. For
random numbers in the last exercise, you may use the java.util.Random class.
Declare any methods you write to be public and static. You may also use the
java.lang.Math class if you need it. You may assume correct user input in these problems.
Exercise 1
Filename: Pi.java
Calculate the value of π from the infinite series:
π=4−
4
3
+
4
5
−
4
7
+
4
9
−
4
11
+…
Print a table that shows the value of π approximated by computing one term of the series,
approximated by two terms, three terms, and so on. Use default precision for output (do not
set any decimal precision).
Start by asking the user how many terms to compute to and then let the user enter the
information. Use this to print a table of the first N terms of the series (where N is the data
entered by the user). Assume the user’s input will be a non-negative integer. Try to match my
sample output as closely as you can. Be aware that the default precision of
System.out.print is different from that of System.out.printf, so if your precision
does not match my output exactly, it is okay as long as you are using the default for whichever
printing function you are using (I used System.out.printf).
Sample Run
(Sample user input is underlined)
Compute to how many terms of the series? 20
terms PI approximation
1
1 4.000000
2 2.666667
3 3.466667
4 2.895238
5 3.339683
6 2.976046
7 3.283738
8 3.017072
9 3.252366
10 3.041840
11 3.232316
12 3.058403
13 3.218403
14 3.070255
15 3.208186
16 3.079153
17 3.200366
18 3.086080
19 3.194188
20 3.091624
Exercise 2
Filename: Reverse.java
Write a static method called reverseDigits that takes a long integer value and returns
that number with its digits reversed. For example, given the value 1459, the method should
return the value 9541 as a long integer.
Write a main() method that enters a loop in which the user is prompted and allowed to
enter any long integer (0 to exit the loop) and the reverseDigits method is used to
compute and return the reversed number. Print this from the main routine.
You may assume the user inputs a positive integer. Try to match the sample run exactly.
Sample Run
(Sample user input is underlined)
Please enter a long integer (0 to quit): 123456
The number reversed is: 654321
Please enter a long integer (0 to quit): 4837946852
The number reversed is: 2586497384
Please enter a long integer (0 to quit): 2345678
The number reversed is: 8765432
Please enter a long integer (0 to quit): 123456789012345678
The number reversed is: 876543210987654321
Please enter a long integer (0 to quit): 234005700
The number reversed is: 7500432
Please enter a long integer (0 to quit): 0
Goodbye!
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Exercise 3
Filename: DiceStats.java
Write a program that does the following:
1. Ask the user to enter how many dice will constitute a roll (Some games require different
numbers of dice per turn. Yahtzee takes 5, Monopoly takes 2, etc.).
2. Ask the user to enter how many rolls they would like to simulate.
3. Create and use an array to keep track of how many times each possible dice sum
appears. Basically, it is a bunch of counters and how many you need depends on how
many dice are rolled per “turn.”
 Hint: The idea is that this array is a frequency array like the example we went over
in class (number 7.7 from the array lecture)
 Hint: You determine how many counters you will need based on the number of dice
rolled per turn. The lowest possible total is all 1s, so the number of dice rolled. The
highest possible total is all 6s, so it is (6 * number_of_dice). Use this to determine
the size of your array.
4. Use a loop to roll the specified number of dice the desired number of times (and
calculate the sum of each roll). Use the array to keep track the number of times each
possible sum appears.
5. Display the results in a table with 3 columns:
(a) the die total
(b) the number of times that total appeared
(c) the percentage of the total rolls that this sum appeared (print the percentage to 2
decimal places)
Try to match the sample runs as closely as possible. Since randomness is involved, the number
of times each sum appears (and the matching percentages) will be different, but if you use the
same number of dice they should be similar to the sample run values (if you roll 2 dice at a
time, you should not get a sum of 12 20% of the time, for example)
Sample Run 1
(Sample user input is underlined)
How many dice will constitute one roll? 2
How many rolls? 100000
Sum # of times Percentage
2 2739 2.74 %
3 5468 5.47 %
4 8365 8.37 %
5 11242 11.24 %
6 13816 13.82 %
7 16779 16.78 %
8 13882 13.88 %
9 11034 11.03 %
10 8316 8.32 %
3
11 5595 5.60 %
12 2764 2.76 %
Sample Run 2
(Sample user input is underlined)
How many dice will constitute one roll? 4
How many rolls? 100000
Sum # of times Percentage
4 83 0.08 %
5 319 0.32 %
6 735 0.74 %
7 1553 1.55 %
8 2655 2.66 %
9 4255 4.26 %
10 6275 6.28 %
11 8161 8.16 %
12 9660 9.66 %
13 10855 10.86 %
14 11200 11.20 %
15 10829 10.83 %
16 9646 9.65 %
17 7865 7.87 %
18 6167 6.17 %
19 4300 4.30 %
20 2685 2.69 %
21 1561 1.56 %
22 799 0.80 %
23 317 0.32 %
24 80 0.08 %
Compiling
Remember that the compile command is javac at the unix command prompt. Compile your
code on linprog.cs.fsu.edu and run your program with the java command.
Preparing for Submission
Pack your files into a single jar-file called hw1.jar with the jar utility. To do this on
linprog.cs.fsu.edu (or another terminal environment) use the following command:
jar cvf hw1.jar Pi.java Reverse.java DiceStats.java
Submitting
I have created a Canvas submission link for the assignment. It is in the Assignments section of
the Canvas course site. Submit your hw1.jar file there.
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