Rotational Cipher

Challenge Overview

Create an implementation of the rotational cipher, also sometimes called the Caesar cipher.

Visit the rotational-cipher exercise on Exercism to read the full instructions and download the exercise files.

Community Solutions

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The following are the top 3 community solutions by stars:

Solution 1 by @jejones3141 (⭐ 5) — View on Exercism
Solution 2 by @jonmcalder (⭐ 6) — View on Exercism
Solution 3 by @katrinleinweber (⭐ 3) — View on Exercism

Source: Exercism r/rotational-cipher

💡 View Solution

rotate <- function(text, key) {
  encode <- function(c) {
    if (c %in% letters) {
      base <- utf8ToInt("a")
    } else if (c %in% LETTERS) {
      base <- utf8ToInt("A")
    } else {
      return(c)
    }
    intToUtf8(base + (utf8ToInt(c) - base + key) %% 26)