PalindromicSubstring.js

/* description : 


Given a string s, return the longest 
palindromic substring in s.


Example 1:
Input: s = "babad"
Output: "bab"
Explanation: "aba" is also a valid answer.

Example 2:
Input: s = "cbbd"
Output: "bb" */

/* ---------------------------------------------------------- */

var longestPalindrome = (s) => {
 let longest = '';
 for (let i = 0; i < s.length; i++) {
 // Check odd-length palindromes
 let left = i, right = i;
 while (left >= 0 && right < s.length && s[left] === s[right]) {
 let palindrome = s.substring(left, right + 1);
 if (palindrome.length > longest.length) {
 longest = palindrome;
 }
 left--;
 right++;
 }
 // Check even-length palindromes
 left = i;
 right = i + 1;
 while (left >= 0 && right < s.length && s[left] === s[right]) {
 let palindrome = s.substring(left, right + 1);
 if (palindrome.length > longest.length) {
 longest = palindrome;
 }
 left--;
 right++;
 }
 }
 return longest;
 
};

console.log(longestPalindrome('cbbd'))