One classic method for composing secret messages is called a square code.
The spaces and punctuation are removed from the English text and the characters are written into a square (or rectangle) and the entire message is downcased. For example, the sentence "If man was meant to stay on the ground god would have given us roots" is 54 characters long, so it is written into a rectangle with 7 rows and 8 columns.
ifmanwas
meanttos
tayonthe
groundgo
dwouldha
vegivenu
sroots
The coded message is obtained by reading down the columns going left to right.
For example, the message above is coded as:
imtgd vsfea rwerm ayoog
oanou uiont nnlvt wttdd
esaoh ghnss eoau
Write a program that, given an English text, outputs the encoded version of that text.
The size of the square (number of columns) should be decided by the length of the message.
If the message is a length that creates a perfect square (e.g. 4, 9, 16, 25, 36, etc), use that number of columns.
If the message doesn't fit neatly into a square, choose the number of columns that corresponds to the smallest square that is larger than the number of characters in the message.
For example, a message 4 characters long should use a 2 x 2 square. A message that is 81 characters long would use a square that is 9 colums wide.
A message between 5 and 8 characters long should use a rectangle 3 characters wide.
Output the encoded text in groups of five letters.
E.g.
crypto = Crypto.new("Have a nice day. Feed the dog & chill out!")
crypto.normalize_plaintext
# => "haveanicedayfeedthedogchillout"
crypto.size
# => 36
crypto.plaintext_segments
# => ["havean", "iceday", "feedth", "edogch", "illout"]
crypto.ciphertext
# => "hifei acedl v..."