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63 lines
2.3 KiB
JavaScript
63 lines
2.3 KiB
JavaScript
/**
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* alphaNumericPlaindrome should return true if the string has alphanumeric characters that are palindrome irrespective of special characters and the letter case
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* @param {string} str the string to check
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* @returns `Boolean`
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*/
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/*****************************************************************************
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* What is a palindrome? https://en.wikipedia.org/wiki/Palindrome
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*
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* The function alphaNumericPlaindrome() recieves a sting with varying formats
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* like "racecar", "RaceCar", and "race CAR"
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* The string can also have special characters
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* like "2A3*3a2", "2A3 3a2", and "2_A3*3#A2"
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*
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* But the catch is, we have to check only if the alphanumeric characters
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* are palindrome i.e remove spaces, symbols, punctuations etc
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* and the case of the characters doesn't matter
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*
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* This is one of the questions/projects that we have to solve for the
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* JavaScript Algorithms and Data Structures course on https://www.freecodecamp.org
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*
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* Author -- Syed Fasiuddin
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* https://github.com/SyedFasiuddin
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*
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****************************************************************************/
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const alphaNumericPlaindrome = (str) => {
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// removing all the special characters and turning everything to lowercase
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const newStr = str.replace(/[^a-zA-Z0-9]*/g, '').toLowerCase()
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// the newStr variable is a string and only has alphanumeric characters all in lowercase
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// making an array of individual characters as it's elements
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const arr = newStr.split('')
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// setting a variable to see if change occurs to it
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let palin = 0
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// making a copy of arr with spread operator
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const arrRev = [...arr]
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// you can use arrRev.reverse() to reverse the array
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// or else you can use the below method
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// iterate through the arr and check the condition of palindrome
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for (let i = 0; i < arr.length; i++) {
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if (arr[i] !== arrRev[arr.length - 1 - i]) {
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// if the string is not palindrome then we change palin varaible to 1
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palin = 1
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}
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}
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// if the string is palindrome then palin variable is never changed
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if (palin == 0) return true
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else return false
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}
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// test cases
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// alphaNumericPlaindrome("eye");
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// alphaNumericPlaindrome("0_0 (: /-\ :) 0-0")
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// alphaNumericPlaindrome("five|\_/|four")
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// alphaNumericPlaindrome("A man, a plan, a canal. Panama")
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export { alphaNumericPlaindrome }
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