Assignment 3: Loops, I did it again!
Due Thursday, September 29, before midnight
The goals of this assignment are:

Work with loops

Work with if statements

Work with accumulator variables
1. Banner
Write a program, Banner.java
, that draws an ascii border around a phrase given by the
user.
Two examples of the running program are shown below. User input is shown in bold.
$ java Banner
Enter a phrase: Welcome, Friends!
Enter a decorator character: +
+++++++++++++++++++++
+ Welcome, Friends! +
+++++++++++++++++++++
$ java Banner
Enter a phrase: Applesauce!
Enter a decorator character: $
$$$$$$$$$$$$$$$
$ Applesauce! $
$$$$$$$$$$$$$$$
Requirements:

Your border should fit around the entered phrase as in the examples.

You can read both the phrase and decorator character as Strings

You can assume the user will enter a single character as a decorator
2. Checkerboard
Write a program, Checkerboard.java
, that asks the user for a size and
uses a nested loop to print a twodimensional sizebysize checkerboard pattern
consisting of dashes and o’s.
$ javac Checkerboard.java
$ java Checkerboard
Enter a size: 11
oooooo
ooooo
oooooo
ooooo
oooooo
ooooo
oooooo
ooooo
oooooo
ooooo
oooooo
3. ISBN
Write a program, ISBN.java
, that computes the checksum and prints the ISBN number
for a given 9digit number.
The ISBN number is 10digit code that uniquely specifies a book. For example, the ISBN number for Harry Potter and the Socerer’s Stone is java ISBN 0747532745
The rightmost digit is a checksum digit that can be computed using the other 9 digits. Suppose we have an ISBN number, defined as
where each \(d_i\) is a digit with value between 0 and 9. For example, for Harry Potter's ISBN number, \(d_{10}\) is 0; \(d_9\) is 7; \(d_8\) is 4; etc.
The ISBN number has the property that the following expression must be a multiple of 11.
Therefore, to find the checksum you should test each digit, from 0 to 9, to find a value for \(d_1\) that results in a number that is a multiple of 11. The value for \(d_1\) is called the checksum digit.
Below are examples of running this program. User input is in bold.
$ java ISBN 817525766
The checksum digit is 0
The full ISBN number is 8175257660
$ java ISBN 074753274
The checksum digit is 5
The full ISBN number is java ISBN 0747532745
Requirements:

Your program must use command line arguments!

Use % to determine whether the ISBN formula is a multiple of 11

You can assume that the input with be a 9 digit number

You should print the checksum along with the 10 digit ISBN number.
Hints:
The input is the first 9 digits of the ISBN number. An easy way to
parse this is to go through each character of the input string and convert each
individually to a digit. One way to do this is use the fact that characters
correspond to numbers "under the hood" according to the ASCII Table.
If we subtract the character '0', we
get the offset of the digit from zero. See below for an example.
Alternatively, you can also use the function
Character.getNumericValue(c); .

String example = "123456789";
for (int i = 0; i < example.length(); i++) {
char c = example.charAt(i);
int digit = c  '0';
System.out.println(digit);
}
4. Poll Predictor
Write a program, Predictor.java
, which predicts a candidate’s likelihood of
victory given its current polling number and margin of error. For example, if a
poll predicts that a candidate has a 47% chance of winning a state with a 6%
margin of error, can we make an overall prediction that the candidate will win
a state?
One way to do this is to simulate an actual vote incorporating the margin of error. Let’s say, a poll (POLL) in a state shows that a candidate is likely to receive 47% of the vote in their favor with a margin of error +/ 6% (MOE). With this information, we can do a simulation of the state’s voting, and arrive at the % of votes received by the candidate in a poll:
SamplePoll = POLL + X * MOE
Where X is a number in the range [1.0..1.0]. For example, if X is 0.5, then
the candidate will receive 0.47 + 0.5 * 0.06 = 0.44. This means, in this
instance, the candidate received only 44% of the votes (i.e. losing the state).
Alternately, if X turns out to be 0.8 then the candidate will receive 0.47
0.8 * 0.06 = 0.518 or 51.8% of the votes cast thereby winning the state.
We can use Java’s Math.random() function to generate values of X in the range [1.0..1.0) and perform a simulation of several sample elections based on POLL and MOE to see if a candidate is likely to win or lose a state. For example,
$ javaintrocs Predictor Keystone 0.47 0.06 1000000
Candidate win likelihood for Keystone state is 25.02%
The above means that after performing 1 million randomized simulated polls based on POLL and MOE the candidate has a 25% likelihood of winning Keystone state. Here are some more examples.
$ javaintrocs Predictor Keystone 0.53 0.06 1000000
Candidate win likelihood for Keystone state is 74.99%
$ javaintrocs Predictor Golden 0.49 0.07 1000000
Candidate win likelihood for Golden state is 42.82%
$ javaintrocs Predictor Nutmeg 0.51 0.02 1000000
Candidate win likelihood for Nutmeg state is 75.01%
You program, Predictor.java
, should take the following command line arguments:

state
: (String) state name. For example, Keystone, Golden, or Nutmeg 
POLL
: (double) polling number, a double in the range [0,1]. For example, 0.53, 0.49, or 0.51 
MOE
: (double) margin of error, a double in range [0,1]. For example, 0.06, 0.07, or 0.02 
N
: (int) number of simulation iterations. For example, 1000000
Your program, Predictor.java
, should implement the following algorithm
wins = 0
Repeat N times
Compute SamplePoll = POLL + randomNumber * MOE
If SamplePoll > 0.5 then
Increment wins by 1
Compute and output overall win likelihood = (wins/N)
STATE 
Poll 
Margin of Error 
Garden 
48% 
3% 
Empire 
53% 
4% 
Nutmeg 
42% 
9% 
Golden 
52% 
4% 
LoneStar 
49% 
5% 
In your writeup, include the likelihoods computed by your program for all states, using N = 1000000.
5. What to handin

The programs,
Banner.java
,Checkerboard.java
,ISBN.java
, andPredictor.java
. 
Make sure each program has a header containing your name, date, and purpose of the program

A brief writeup containing your name, assignment number, and a few sentences about how long you spent on the assignment and any interesting bugs you solved. Don’t forget to include the likelihoods computed by your Predictor!
5.1. How to handin

Copy your programs and writeup to your dropbox, into the folder called
A03
.