Computer Science Help, c++

One method of encoding messages is known as the "expanding square code". This method encodes message by placing the character of the message in an odd

order square matrix row by row, and then retrieving them in a clockwise expanding square spiral from the center of the matrix. If the message is not

exactly the right length to fill the matrix, the rest of the matrix is filled with asterisk characters (*).

For example, the two square matrices below show the order in which the characters are placed in the matrix,

and the order in which they are retrieved. Notice that the order of retrieval begins at the center, then proceed to the right, and then spirals clockwise

Order In Order Out

1 2 3 4 5 21 22 23 24 25

6 7 8 9 10 20 7 8 9 10

11 12 13 14 15 19 6 1 2 11

16 17 18 19 20 18 5 4 3 12

21 22 23 24 25 17 16 15 14 13

Message In: "This is a test message!!"

Message Out: "stssees a a*!!egmtiThis "

Your program must be able to encode messages by this method. The input (from standard in) will consist of a string of text entered by the user,

containing an unknown number of characters N (0 < N <= 1000). From the length of the message, you should determine the minimum odd order required for the matrix,

and perform the specified operation. The output for you program will be the encoded message.