30-seconds-of-code/snippets/anagrams.md

anagrams

⚠️ WARNING: This function's execution time increases exponentially with each character. Anything more than 8 to 10 characters will cause your browser to hang as it tries to solve all the different combinations.

Generates all anagrams of a string (contains duplicates).

Use recursion. For each letter in the given string, create all the partial anagrams for the rest of its letters. Use Array.map() to combine the letter with each partial anagram, then Array.reduce() to combine all anagrams in one array. Base cases are for string length equal to 2 or 1.

const anagrams = str => {
  if (str.length <= 2) return str.length === 2 ? [str, str[1] + str[0]] : [str];
  return str
    .split('')
    .reduce(
      (acc, letter, i) =>
        acc.concat(anagrams(str.slice(0, i) + str.slice(i + 1)).map(val => letter + val)),
      []
    );
};

anagrams('abc'); // ['abc','acb','bac','bca','cab','cba']