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alphaNumericPlaindrome optamization #857

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Nov 29, 2021
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alphaNumericPlaindrome optamization #857

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44 changes: 10 additions & 34 deletions String/AlphaNumericPalindrome.js
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Original file line number Diff line number Diff line change
@@ -1,12 +1,10 @@
/**
* alphaNumericPlaindrome should return true if the string has alphanumeric characters that are palindrome irrespective of special characters and the letter case
* @param {string} str the string to check
* @returns `Boolean`
*/

/*****************************************************************************
* What is a palindrome? https://en.wikipedia.org/wiki/Palindrome
*
* @function alphaNumericPlaindrome
* @description alphaNumericPlaindrome should return true if the string has alphanumeric characters that are palindrome irrespective of special characters and the letter case.
* @param {string} str the string to check
* @returns {Boolean}
* @see [Factorial](https://en.wikipedia.org/wiki/Palindrome)
* @example
* The function alphaNumericPlaindrome() receives a string with varying formats
* like "racecar", "RaceCar", and "race CAR"
* The string can also have special characters
Expand All @@ -16,41 +14,19 @@
* are palindrome i.e remove spaces, symbols, punctuations etc
* and the case of the characters doesn't matter
*
* This is one of the questions/projects that we have to solve for the
* JavaScript Algorithms and Data Structures course on https://www.freecodecamp.org
*
* Author -- Syed Fasiuddin
* https://github.com/SyedFasiuddin
*
****************************************************************************/

const alphaNumericPlaindrome = (str) => {
// removing all the special characters and turning everything to lowercase
const newStr = str.replace(/[^a-zA-Z0-9]*/g, '').toLowerCase()
// the newStr variable is a string and only has alphanumeric characters all in lowercase

// making an array of individual characters as it's elements
const arr = newStr.split('')

// setting a variable to see if change occurs to it
let palin = 0

// making a copy of arr with spread operator
const arrRev = [...arr]
// you can use arrRev.reverse() to reverse the array
// or else you can use the below method

// iterate through the arr and check the condition of palindrome
for (let i = 0; i < arr.length; i++) {
if (arr[i] !== arrRev[arr.length - 1 - i]) {
// if the string is not palindrome then we change palin variable to 1
palin = 1
for (let i = 0; i < newStr.length; i++) {
if (newStr[i] !== newStr[newStr.length - 1 - i]) {
return false
}
}

// if the string is palindrome then palin variable is never changed
if (palin === 0) return true
else return false
return true
}

export { alphaNumericPlaindrome }