Hello,

I'm new here, and I need to make a program that uses various encryption methods. I've done the case conversion, writing in reverse order, and eliminating the spaces encryptions.

I'm having problems doing the following:
*Putting the characters in the string into blocks of 2, 3, 4, or any number chosen by the user
*Using a set offset, for example:
with an offset of 3, an A should become a D, a B should become an E, etc. (each character is substituted with the letter 3 alphabets away from it); the 'offset number' is selected by the user
*using a random substitution so that each of the letters used in the string is assigned a random 'equivalent' alphabet that is not repeated, example:
if message is: "this is a cat",
the encryption MAY BE: "ptsj sj k mkp"
(where the random would be: t=p,h=t,i=s,s=j,a=k,c=m)

Can somebody please just 'explain' how to approach the problem, and then i'll try to program it and see how it goes?

Thank you!
Juwairia

the easiest way i could see is to cast the chars to ints and get their ascii value, eg: A=65, then add your offset to this and convert back to a char, thus:
offset of 3:
A = 65 + 3 = 68 = D

the captials come first, then the small letters. You may want to run a check that you don't exceed the value 122 as this is small z. There are also the values of some symbols, such as: £Ä you may want to include or not. Just something to consider when writting this.

Thank you sooo much!
Also, would you know how to put the characters in the string into blocks of 2, 3, 4, or any number chosen by the user?
Thanks again!
Juwairia