Files
JavaScript/String/AlphaNumericPalindrome.js
Fahim Faisaal cbc669aa9d merge: Upgraded Algorithm of alpha numeric palindrome (#1006)
* feat: improved memoize function

used Map instead of object & used the JSON.stringfy method for generate a valid string as a key

* docs: modified documentation

* style: format with standard

* docs: modified stringify doc

* refactor: remove two repetition implementation

* feat: added validation, test codes

* chore: remove useless words

* feat: added types for jest

* chore: added link box

* feat: added new validation test casses & methods

* style: formated with standard

* feat: added parse method & test cases

* docs: added js docs

* chore: added default import export

* feat: imporved algorithm via replace method

* test: added two test cases

* feat: added jest type for suggestions

* feat: added `reduceRight` & `trim` method

* chore: added helper variable

* feat: added new rotation option

* Revert "chore: added helper variable"

This reverts commit 489544da0a3d479910fbea020d3be3d0d10681bf.

* remove: yarn lock

* chore: fix grammer

* feat: used replace method & added test case

* feat: remove revert

* chore: added new line

* feat: optimized algo n to n / 2 & replaced test cases

* chore: update node version

* chore: set node version to lts

* chore: updated the node version & added engines prop

* resolve: removed while loop

* chore: added right shift ops comment

* chore: update comment

* chore: removed abs

Co-authored-by: Rak Laptudirm <raklaptudirm@gmail.com>
2022-05-07 17:42:50 +05:30

36 lines
1.3 KiB
JavaScript

/**
* @function alphaNumericPalindrome
* @description alphaNumericPalindrome 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 [Palindrome](https://en.wikipedia.org/wiki/Palindrome)
* @example
* The function alphaNumericPalindrome() receives a string with varying formats
* like "racecar", "RaceCar", and "race CAR"
* The string can also have special characters
* like "2A3*3a2", "2A3 3a2", and "2_A3*3#A2"
*
* But the catch is, we have to check only if the alphanumeric characters
* are palindrome i.e remove spaces, symbols, punctuations etc
* and the case of the characters doesn't matter
*/
const alphaNumericPalindrome = (str) => {
if (typeof str !== 'string') {
throw new TypeError('Argument should be string')
}
// removing all the special characters and turning everything to lowercase
const newStr = str.replace(/[^a-z0-9]+/ig, '').toLowerCase()
const midIndex = newStr.length >> 1 // x >> y = floor(x / 2^y)
for (let i = 0; i < midIndex; i++) {
if (newStr.at(i) !== newStr.at(~i)) { // ~n = -(n + 1)
return false
}
}
return true
}
export default alphaNumericPalindrome