LeetCode(1328) -- Break a Palindrome

Problem

Given a palindromic string palindrome, replace exactly one character by any lowercase English letter so that the string becomes the lexicographically smallest possible string that isn’t a palindrome.

After doing so, return the final string. If there is no way to do so, return the empty string.

Example 1:

Input: palindrome = "abccba"
Output: "aaccba"

My Solution

class Solution {
    public String breakPalindrome(String palindrome) {
        if (palindrome.length() <= 1) {
            return "";
        }
        char[] chars = palindrome.toCharArray();
        for (int i = 0; i < palindrome.length() / 2; i++) {
            if (chars[i] != 'a') {
                chars[i] = 'a';
                return new String(chars);
            }
        }
        chars[palindrome.length() - 1] = 'b';
        return new String(chars);
    }
}