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35 lines
1.3 KiB
Markdown
35 lines
1.3 KiB
Markdown
# caesar-cipher
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Created by [@theoludwig](https://github.com/theoludwig) on 25 June 2021.
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## Instructions
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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.
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### Example of the alphabet with a shift of +3 (shift to the right)
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```text
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Alphabet original : ABCDEFGHIJKLMNOPQRSTUVWXYZ
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Alphabet rotated +3 : DEFGHIJKLMNOPQRSTUVWXYZABC
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```
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Create a function that will return the sentence after shifting the alphabet.
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- If it is a **positive** number then we shift the alphabet to the **right**
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- If it is a **negative** number then we shift the alphabet to the **left**
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### Example of Inputs
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```py
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'ANTHONY' # a character string (all capital letters)
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'-2' # an integer, the shift in the alphabet
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```
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## Source
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[Wikipedia - Caesar cipher](https://en.wikipedia.org/wiki/Caesar_cipher)
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## Examples
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See the `test` folder for examples of input/output.
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