0005-longest-palindromic-substring.kt

class Solution {
    fun longestPalindrome(s: String): String {
        
        var start = 0 // start of longest palindrom
        var maxL = 0
        
        for(i in 0 until s.length){
            
            //odd length palindrom
            var l = i
            var r = i
            while(l >= 0 && r < s.length && s[l] == s[r]){
                if(r - l + 1 > maxL) {//index to size +1
                    start = l
                    maxL = (r - l + 1)
                } 
                l--
                r++
            }
            
            //even length palindrom
            l = i
            r = i + 1
            while(l >= 0 && r < s.length && s[l] == s[r]){
                if(r - l + 1 > maxL) {//index to size +1
                    start = l
                    maxL = (r - l + 1)
                } 
                l--
                r++
            }
            
        }
        
        return s.substring(start, start+maxL)
    }
}