Caesar Cipher. Read in from text file question.

[Yezman]

So I have do decrypt a Caesar Cipher from a text file. It looks like this

<2D or <24A or <-2F (go down -2, so up 2) or <4TA<2

And I am so lost. I have been looking up stuff and attempting to use peek and atoi which I have never heard of until today.

When ever a < is read. The following numbers and signs determine the shift value. And in the last example, if the start of the text file has another '<' or '>' in it, they it adds or subtracts them to the shift value.


So far my code looks like this. You might want to cover your eyes.

http://pastebin.com/tcnxFZiY

My approach is to just read 1 character. Then have a bunch of if's and the loop through the whole text file till I hit the end trigger '#'. I am really having trouble with my shiftMod function. I just added some atoi thing that I had to read about by myself.

Can anyone help me with that function. The goal is to first figure out if it is a '<' or a '>' as done with the first ifs. Then I have to read the next character(s) that are numbers, and STOP at the first alpha. Ex: >24D. It reads the >, but i can't figure out how to read the 2 then the 4, to make the shift value UP 24 letters. So D would wrap around to F.

Should I read them as characters or ints? Ints would be easier, but I have no idea how to pull them out of the .txt file.

Any help would be amazing. Thank you!

[Pravesh Koirala]

Read them as int and then increase the char by the int.
For <24A

//Read 24 in d (DIY)
//Read A in c
c+=d

Let me know if that helps