// An [Anagram](https://en.wikipedia.org/wiki/Anagram) is a string that is a word or phrase formed by rearranging the letters of a different word or phrase, typically using all the original letters exactly once. Anagram check is not case-sensitive;

/**

* @function checkAnagramRegex

* @param {string} str1

* @param {string} str2

* @returns {boolean}

* @description - check anagram with the help of Regex

* @example - checkAnagramRegex('node', 'deno') => true

* @example - checkAnagramRegex('Eleven plus two', 'Twelve plus one') => true

*/

const checkAnagramRegex = (str1, str2) => {

// check that inputs are strings.

if (typeof str1 !== 'string' || typeof str2 !== 'string') {

throw new TypeError('Both arguments should be strings.')

}

// If both strings have not same lengths then they can not be anagram.

if (str1.length !== str2.length) {

return false

}

/**

* str1 converted to an array and traverse each letter of str1 by reduce method

* reduce method return string which is empty or not.

*/

return ![...str1].reduce(

(str2Acc, cur) => str2Acc.replace(new RegExp(cur, 'i'), ''), // remove the similar letter from str2Acc in case-insensitive

str2

)

}

/**

* @function checkAnagramMap

* @description - check anagram via using HashMap

* @param {string} str1

* @param {string} str2

* @returns {boolean}

* @example - checkAnagramMap('node', 'deno') => true

* @example - checkAnagramMap('Eleven plus two', 'Twelve plus one') => true

*/

const checkAnagramMap = (str1, str2) => {

// check that inputs are strings.

if (typeof str1 !== 'string' || typeof str2 !== 'string') {

throw new TypeError('Both arguments should be strings.')

}

// If both strings have not same lengths then they can not be anagram.

if (str1.length !== str2.length) {

return false

}

const str1List = Array.from(str1.toUpperCase()) // str1 to array

// get the occurrences of str1 characters by using HashMap

const str1Occurs = str1List.reduce(

(map, char) => map.set(char, map.get(char) + 1 || 1),

new Map()

)

for (const char of str2.toUpperCase()) {

// if char has not exist to the map it's return false

if (!str1Occurs.has(char)) {

return false

}

let getCharCount = str1Occurs.get(char)

str1Occurs.set(char, --getCharCount)

getCharCount === 0 && str1Occurs.delete(char)

}

return true

}

export { checkAnagramRegex, checkAnagramMap }