給定一個字符串，寫出所有該字符串的子串爲迴文串的子串

package com.xmd.quartz.test.string;

import java.util.*;

/**
 * User: xumengdi
 * Date: 2019/9/9
 */
public class TestTwo {

    public static void main(String[] args) {
        //迴文串有：a,a,b,b,a,a,c
        //         aa
        //         bb
        //         aabbaa
        //         abba
        String str = "aabbaac";
        List<String> temp = new ArrayList<String>();
        int begin = 0,last = 0;
        while(last < str.length()){
            temp.add(str.substring(begin,last+1));
            begin = last+1;
            last++;
        }
        Collections.reverse(temp);
        String first = "";
        List<String> res = new ArrayList<>();
        int count = 0;
        int i = 0;
        while(count<temp.size()){
            for(i=0;i<temp.size();i++){
                first = first+temp.get(i);
                res.add(first);
            }
            first = "";
            temp = temp.subList(1,temp.size());
        }
        List<List<String>> result = new ArrayList<>();
        for(int n=0;n<res.size();n++){
            String before = res.get(n);
            String after = new StringBuffer(before).reverse().toString();
            if(before.equals(after)){
                if(before.length()>1){
                    List<String> subList = new ArrayList<>();
                    subList.add(before);
                    result.add(subList);
                }
            }
        }
        Set<List<String>> set = new HashSet<List<String>>();
        for(int s =0;s<result.size();s++){
           set.add(result.get(s));
        }
        List<String> strlist = new ArrayList<>();
        strlist.add("a,a,b,b,a,a,c");
        set.add(strlist);
        System.out.println(set.toString());
    }
}