10-anagrams.js

// An anagram is any word or phrase that uses the letters of a given ("subject") word or phrase in another, rearranged order. 
// Write a function that creates an anagram list, 
// listing all the rearrangements of a given word. 
// For example, if the user types "east", the program should list all 24 permutations, 
// including "eats", "etas", "teas", and non-words like "tsae".

// Hint: For your algorithm, you might want to think about a prefix and use that to create the new words. 
// For example, given "east", use "e" as a prefix and place it in front of all 6 permutations of "ast" — "ast", "ats", "sat", "sta", "tas", and "tsa". 
// This will give you the words "east", "eats", "esat", "esta", "etas", and "etsa". 
// Continue this way until you find all the anagrams for "east". 
// Then you can use "a" as a prefix and permute the remaining words "est". For "east", there should be 24 words.

const anagrams = (input) => {
    if (input.length === 1) return [input];
    let resultArray = [];
    let inputArray = input.split("");
    for (let i = 0; i < inputArray.length; i++){
        const anagramResults = anagrams(spliceNoMutate(inputArray, i).join(""));
        for (let j = 0; j < anagramResults.length; j++){
            resultArray.push(inputArray[i] + anagramResults[j]);
        }
    }
    return resultArray;
}

const spliceNoMutate = (input, index) => {
    let result = [...input];
    result.splice(index, 1);
    return result; 
}

console.log(anagrams("subject"))