couldn't display the full code on the website for some reason... public String longestPalindrome(String s) { char[] ca = s.toCharArray(); int rs = 0, re = 0; int max = 0; for(int i = 0; i < ca.length; i++) { if(isPalindrome(ca, i - max - 1, i)) { rs = i - max - 1; re = i; max += 2; } else if(isPalindrome(ca, i - max, i)) { rs = i - max; re = i; max += 1; } } return s.substring(rs, re + 1); } private boolean isPalindrome(char[] ca, int s, int e) { if(s < 0) return false; while(s < e) { if(ca[s++] != ca[e--]) return false; } return true; }