Program $6$ Basic: Brutus

Goal:

Remember how last program it output all possibilities for the Caesar shift and we$,$ the humans, had to

read through to find the one in English? In this program, you$$re going to extend your Caesar program so

that it can determine which shift is the English text!

How can a computer know English?

The simple answer is it doesn$$t$.$ However, we can provide it a list of words and have the computer check

to see if a word is in the list. Then if enough words are found, the computer can say yeah, that$$s

probably the English one.

The simplest way to do this $($the way we$$ll do it for this program$)$ is to make an array of words found in

the words.txt file...

$1)$ Read a line of the file.

$2)$ Get rid of

and any non$-$letter characters.

$3)$ Append it to an array $($called dictionary or something similar$).$

Then to determine if a shifted line is in English...

$1)$ Split the shifted line by its spaces so you have an array of words.

$2)$ For each word in the array, see if it$$s in the dictionary array. If it is$,$ increase a count by $1.$

a$.$ HINT: if word in dictionary: will do that for you!

$3)$ After you$$ve checked every word in the shifted line, see if your count is greater than or equal to

$40\%$ of the number of words in the shifted line.

a$.$ If it is$,$ output that line and which shift it is$.$

b$.$ Else, do the next shift then determine if that one is in English.

Specifications:

$$ Read the file one line at a time.

$$ Output the original line.

$$ Apply every possible Caesar shift to the input line.

o NOTE: You are only shifting alphabetic characters $($letters$)$ punctuation and spaces

should remain intact!

$$ For each shift, determine if it$$s in English. Output only the English shift!

o NOTE: You may be $$killing$$ punctuation to determine if a word is in the dictionary, but

your output must have the punctuation intact!

$$ Time the whole thing like you did last program.

Constraints:

$$ You must have at least one subroutine that applies a single shift to the line. You may include

additional subroutines.

$$ Your output must show the correct shift as instructed.

$$ Output is worded like the sample below.

$$ You must comment your source code appropriately, include an informative header at the top,

and use good coding style.

$$ You must use meaningful variable names.

Hints:

$$ Fix all bugs from the last program before you begin $$ if Caesar didn$$t work, Brutus won$$t$!$

$$ Make a smaller file from the one I gave you for testing purposes, like $5$ or $6$ lines. It$$ll save you

time as you try to develop your algorithm. Just remember: Before you submit your code, make

sure it works for the original file!

$$ Yes, all letters in the input file are CAPS.

$$ Since both the words for the dictionary and the words from the shift may have non$-$letter

characters, you$$ll probably want one subroutine to get rid of punctuation!