Woburn Challenge 1995
You have just found the secret instructions on how to encode a message:
"Calculate the message length and round up to the nearest multiple of 5. Write out the message in rows of 5 characters each until the message is complete. Send the message a column at a time from left to right."
For example, suppose the message is
THIS IS A CODED MESSAGE.
It is 23 characters long so two spaces are added at the end to make it 25 characters long. The rows of 5 characters are:
1 2 3 4 5 T H I S I S A C O D E D M E S S A G E
The characters are sent one column at a time from left to right (a period indicates a space):
The input will consist of 5 commands to encode/decode a message.
The first line of each command is a character to indicate what your program should do:
D means decode,
E means encode.
The second line of each command will contain the text to encode/decode.
The decoded/encoded message for each test case.
(note that spaces, not periods will appear in the input/output)
D TIC.AHSOMGI.DEESAES...DS E MEET.ME.IN.THE.PARK.TONIGHT.AT.SEVEN
(and 3 more commands)