Crypto Square
Level 4
10 Points
Instructions
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 down-cased.
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 into a rectangle as square as possible. The size of the rectangle should be decided by the length of the message.
If c is the number of columns and r is the number of rows, then for the rectangle r x c find the smallest possible integer c such that:
r * c >= length of message,- and
c >= r, - and
c - r <= 1.
Our normalized text is 54 characters long, dictating a rectangle with c = 8 and r = 7:
"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:
"imtgdvsfearwermayoogoanouuiontnnlvtwttddesaohghnsseoau"Output the encoded text in chunks that fill perfect rectangles (r X c), with c chunks of r length, separated by spaces.
For phrases that are n characters short of the perfect rectangle, pad each of the last n chunks with a single trailing space.
"imtgdvs fearwer mayoogo anouuio ntnnlvt wttddes aohghn sseoau "Notice that were we to stack these, we could visually decode the ciphertext back in to the original message:
"imtgdvs"
"fearwer"
"mayoogo"
"anouuio"
"ntnnlvt"
"wttddes"
"aohghn "
"sseoau "Crypto Square
Level 4
10 Points
Instructions
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 down-cased.
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 into a rectangle as square as possible. The size of the rectangle should be decided by the length of the message.
If c is the number of columns and r is the number of rows, then for the rectangle r x c find the smallest possible integer c such that:
r * c >= length of message,- and
c >= r, - and
c - r <= 1.
Our normalized text is 54 characters long, dictating a rectangle with c = 8 and r = 7:
"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:
"imtgdvsfearwermayoogoanouuiontnnlvtwttddesaohghnsseoau"Output the encoded text in chunks that fill perfect rectangles (r X c), with c chunks of r length, separated by spaces.
For phrases that are n characters short of the perfect rectangle, pad each of the last n chunks with a single trailing space.
"imtgdvs fearwer mayoogo anouuio ntnnlvt wttddes aohghn sseoau "Notice that were we to stack these, we could visually decode the ciphertext back in to the original message:
"imtgdvs"
"fearwer"
"mayoogo"
"anouuio"
"ntnnlvt"
"wttddes"
"aohghn "
"sseoau "