Help with project...

Question

I have aproject to do in my cs class. I seriously do not know what to do here:
"For this project you will write a program that will aid in the cracking of a substitution cipher. Basically, it is a form of frequency analysis. Your program will read in a String as input from the user and count the number of times each letter appears in the String. It will then print out the frequency of each letter, along with a decimal frequency or percentage (your choice). You must use an array for this program - you will be severely penalized for not using an array. After running your program your output may look something like this:
Welcome to Letter Frequency Analyzer v. 1.0
Enter a String to be analyzed: The quick brown fox jumps over the lazy dog.
Letter Frequencies
==================
A12.86%
B12.86%
C12.86%
D12.86%
E38.57%
F12.86%
G12.86%
H25.71%
I12.86%
J12.86%
K12.86%
L12.86%
M12.86%
N12.86%
O411.43%
P12.86%
Q12.86%
R25.71%
S12.86%
T25.71%
U25.71%
V12.86%
W12.86%
X12.86%
Y12.86%
Z12.86%
How does this help crack a substitution cipher? By using the letter frequencies of letters in the English language, we can make educated guesses about which letters are substituted for the most common letters (ie. the most common would be e, the next most common would be t, etc). This, of course, would not work for some ciphertexts (like the one in the example), but it should work for most of the cryptogram puzzles that you find in the newspaper.
Hints: Your array should contain 26 elements that you will store the frequency of each letter. The main part of your program will first convert the input String to uppercase, and then use a for loop to go through each letter of the String, incrementing the appropriate index in the array. You do not need a 26 case switch statement to do this! You can cleverly use casting and the unicode values of each letter (see the appendix in your book) to index into the array. My version of this program (that produced the output above) was only 31 lines of code (including 3 blank lines, 5 lines with only brackets, the class and main method definitions, an import statement, etc - in other words, I wrote it just like I write any other program). If you can keep the number of lines in your program at or below 45 (and maintain good coding style), you will receive a 10 point bonus for this project! (the 45 lines do not include the normal 5 line header required at the top of all source code submissions)"
Wtf mate??
Your help is greatly appreciated!
Steve

Answer 1

One of the unwritten rules of this forum is that we don't do other people's homework. But I will give you a hint:
You can cast a character to an integer, if you do you get its unicode value as a number A is \u0041 (in hexadecimal), so the number you get is 65. B is 66, Z is 90.