https://leetcode.com/problems/longest-palindromic-substring/ = 0 && k < s.length() && s.charAt(j) == s.charAt(k)) { j--; k++; } if (maxLen < k - j - 1) { left = j + 1; maxLen = k - j - 1; } } public String longestPalindrome(String s) { int len = s.length(); if (len < 2) { return s; } for (int i = 0; i < len - 1; i++) { expand(s, i, i + 1); expand(s, i, i + 2); } return s.substring(left, left + m..