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exercism fetch ecmascript crypto-square

Crypto Square

Implement the classic method for composing secret messages called a square code.

Given an English text, output the encoded version of that text.

First, the input is normalized: the spaces and punctuation are removed from the English text and the message is downcased.

Then, the normalized characters are broken into rows. These rows can be regarded as forming a rectangle when printed with intervening newlines.

For example, the sentence

If man was meant to stay on the ground, god would have given us roots.

is normalized to:

ifmanwasmeanttostayonthegroundgodwouldhavegivenusroots

The plaintext should be organized in to a rectangle. The size of the rectangle (r x c) should be decided by the length of the message, such that c >= r and c - r <= 1, where c is the number of columns and r is the number of rows.

Our normalized text is 54 characters long, dictating a rectangle with c = 8 and r = 7:

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ifmanwas
meanttos
tayonthe
groundgo
dwouldha
vegivenu
sroots

The coded message is obtained by reading down the columns going left to right.

The message above is coded as:

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imtgdvsfearwermayoogoanouuiontnnlvtwttddesaohghnsseoau

Output the encoded text in chunks. Phrases that fill perfect squares (r X r) should be output in r-length chunks separated by spaces. Imperfect squares will have n empty spaces. Those spaces should be distributed evenly across the last n rows.

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imtgdvs fearwer mayoogo anouuio ntnnlvt wttddes aohghn sseoau

Notice that were we to stack these, we could visually decode the cyphertext back in to the original message:

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imtgdvs
fearwer
mayoogo
anouuio
ntnnlvt
wttddes
aohghn
sseoau

Setup

Go through the setup instructions for ECMAScript to install the necessary dependencies:

http://exercism.io/languages/ecmascript/installation

Requirements

Install assignment dependencies:

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$ npm install

Making the test suite pass

Execute the tests with:

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$ npm test

In the test suites all tests but the first have been skipped.

Once you get a test passing, you can enable the next one by changing xtest to test.

Source

J Dalbey's Programming Practice problems http://users.csc.calpoly.edu/~jdalbey/103/Projects/ProgrammingPractice.html

Submitting Incomplete Solutions

It's possible to submit an incomplete solution so you can see how others have completed the exercise.