mirror of
https://github.com/theoludwig/programming-challenges.git
synced 2024-11-09 22:08:58 +01:00
35 lines
1.3 KiB
Markdown
35 lines
1.3 KiB
Markdown
# caesar-cipher
|
|
|
|
Created by [@Divlo](https://github.com/Divlo) on 25 June 2021.
|
|
|
|
## Instructions
|
|
|
|
In cryptography, a Caesar cipher, also known as Caesar's cipher, the shift cipher, Caesar's code or Caesar shift, is one of the simplest and most widely known encryption techniques. It is a type of substitution cipher in which each letter in the plaintext is replaced by a letter some fixed number of positions down the alphabet. For example, with a left shift of -3, D would be replaced by A, E would become B, and so on. The method is named after Julius Caesar, who used it in his private correspondence.
|
|
|
|
### Example of the alphabet with a shift of +3 (shift to the right)
|
|
|
|
```text
|
|
Alphabet original : ABCDEFGHIJKLMNOPQRSTUVWXYZ
|
|
Alphabet rotated +3 : DEFGHIJKLMNOPQRSTUVWXYZABC
|
|
```
|
|
|
|
Create a function that will return the sentence after shifting the alphabet.
|
|
|
|
- If it is a **positive** number then we shift the alphabet to the **right**
|
|
- If it is a **negative** number then we shift the alphabet to the **left**
|
|
|
|
### Example of Inputs
|
|
|
|
```py
|
|
'ANTHONY' # a character string (all capital letters)
|
|
'-2' # an integer, the shift in the alphabet
|
|
```
|
|
|
|
## Source
|
|
|
|
- [Wikipedia - Caesar cipher](https://en.wikipedia.org/wiki/Caesar_cipher)
|
|
|
|
## Examples
|
|
|
|
See the `test` folder for examples of input/output.
|