对称子字符串的最大长度

题目：输入一个字符串，输出该字符串中对称的子字符串的最大长度。比如输入字符串“google”，由于该字符串里最长的对称子字符串是“goog”，因此输出4。

public class Test46 {/** * @param args */public static int f(String str) {int length = str.length();int max = 1;int s1 = 0;int s2 = 1;int s3 = 0;int low;int high;int len;for (int i = 0; i < str.length(); i++) {if (i == 0) {if (str.charAt(i) == str.charAt(i + 1)) {max = 2;}continue;}low = i - 1;high = i;while (low >= 0 && high <= length - 1) {if (str.charAt(low) == str.charAt(high)) {s1 += 2;}low--;high++;}low = i - 1;high = i + 1;while (low >= 0 && high <= length - 1) {if (str.charAt(low) == str.charAt(high)) {s2 += 2;}low--;high++;}low = i;high = i + 1;while (low >= 0 && high <= length - 1) {if (str.charAt(low) == str.charAt(high)) {s3 += 2;}low--;high++;}System.out.println(i + " s1 = " + s1);System.out.println(i + " s2 = " + s2);System.out.println(i + " s3 = " + s3);len = (s1 > s2 ? s1 : s2) > s3 ? (s1 > s2 ? s1 : s2) : s3;max = max > len ? max : len;s1 = 0;s2 = 1;s3 = 0;}return max;}public static void main(String[] args) {// TODO Auto-generated method stubString str = "gogogle";System.out.println(f(str));}}

参考资料：http://zhedahht.blog.163.com/blog/static/25411174201063105120425/