题解 | 最长回文子串

import java.util.*;


public class Solution {
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     *
     *
     * @param A string字符串
     * @return int整型
     */
    public int getLongestPalindrome (String A) {
        if (A == null || A.isEmpty()) {
            return 0;
        }
        StringBuffer sb = new StringBuffer("#");
        for (int i = 0; i < A.length(); i++) {
            sb.append(A.charAt(i));
            sb.append("#");
        }
        A = sb.toString();
        int max = 0;
        for (int i = 0; i <= A.length() - 1; i++) {
            int left = i - 1;
            int right = i + 1;
            while (left >= 0 && right < A.length() && A.charAt(left) == A.charAt(right)) {
                max = Math.max(max, right - left + 1);
                left--;
                right++;
            }
        }
        return max / 2;
    }
}