Project: break the code

Learn

Decoding is the same sum backwards: take the shift away instead of adding it. Wrapping works in both directions because % 26 keeps the answer between 0 and 25, even when the number before it is negative. Put the steps in a function, decode(text, shift), and you can use it on any message.

Your task

Write decode(text, shift) that undoes a shift code, and use it to read wkh txlfn eurzq ira (shift 3).

Stretch challenge

Try every shift from 1 to 25 on an unknown message with a loop, and look for the one that makes words.

← Project: a secret codeProject: rock, paper, scissors referee →

Press Run to see what your program prints.